Add square conformal projections from libproject

This commit adds five new projections to PROJ:

    adams_hemi: Adams Hemisphere in a Square
    adams_wsI:  Adams World in a Square I
    adams_wsII: Adams World in a Square II
    guyou:      Guyou
    peirce_q:   Pierce Quincuncial

The code originates from Gerry Evendens libproject and has been adapted
to work with modern PROJ. To ensure that the modified code works as
intended extensive test data has been created using libproject and
sproj so that no errors occured when porting from libproject to PROJ.
The test data is wrapped in a gie files. All test cases reproduce
results from libproject at the mm level.

11 files changed, 215 insertions, 0 deletions

diff --git a/docs/source/operations/projections/adams_hemi.rst b/docs/source/operations/projections/adams_hemi.rst
new file mode 100644
index 00000000..96fe78f1
--- /dev/null
+++ b/docs/source/operations/projections/adams_hemi.rst
@@ -0,0 +1,42 @@
+.. _adams_hemi:
+
+********************************************************************************
+Adams Hemisphere in a Square
+********************************************************************************
+
++---------------------+----------------------------------------------------------+
+| **Classification**  | Miscellaneous                                            |
++---------------------+----------------------------------------------------------+
+| **Available forms** | Forward spherical projection                             |
++---------------------+----------------------------------------------------------+
+| **Defined area**    | Global                                                   |
++---------------------+----------------------------------------------------------+
+| **Alias**           | adams_hemi                                               |
++---------------------+----------------------------------------------------------+
+| **Domain**          | 2D                                                       |
++---------------------+----------------------------------------------------------+
+| **Input type**      | Geodetic coordinates                                     |
++---------------------+----------------------------------------------------------+
+| **Output type**     | Projected coordinates                                    |
++---------------------+----------------------------------------------------------+
+
+
+.. figure:: ./images/adams_hemi.png
+   :width: 500 px
+   :align: center
+   :alt:   Adams Hemisphere in a Square
+
+   proj-string: ``+proj=adams_hemi``
+
+Parameters
+################################################################################
+
+.. note:: All parameters are optional.
+
+.. include:: ../options/lon_0.rst
+
+.. include:: ../options/R.rst
+
+.. include:: ../options/x_0.rst
+
+.. include:: ../options/y_0.rst
diff --git a/docs/source/operations/projections/adams_ws1.rst b/docs/source/operations/projections/adams_ws1.rst
new file mode 100644
index 00000000..3283ff57
--- /dev/null
+++ b/docs/source/operations/projections/adams_ws1.rst
@@ -0,0 +1,42 @@
+.. _adams_ws1:
+
+********************************************************************************
+Adams World in a Square I
+********************************************************************************
+
++---------------------+----------------------------------------------------------+
+| **Classification**  | Miscellaneous                                            |
++---------------------+----------------------------------------------------------+
+| **Available forms** | Forward spherical projection                             |
++---------------------+----------------------------------------------------------+
+| **Defined area**    | Global                                                   |
++---------------------+----------------------------------------------------------+
+| **Alias**           | adams_ws1                                                |
++---------------------+----------------------------------------------------------+
+| **Domain**          | 2D                                                       |
++---------------------+----------------------------------------------------------+
+| **Input type**      | Geodetic coordinates                                     |
++---------------------+----------------------------------------------------------+
+| **Output type**     | Projected coordinates                                    |
++---------------------+----------------------------------------------------------+
+
+
+.. figure:: ./images/adams_ws1.png
+   :width: 500 px
+   :align: center
+   :alt:   Adams World in a Square I
+
+   proj-string: ``+proj=adams_ws1``
+
+Parameters
+################################################################################
+
+.. note:: All parameters are optional.
+
+.. include:: ../options/lon_0.rst
+
+.. include:: ../options/R.rst
+
+.. include:: ../options/x_0.rst
+
+.. include:: ../options/y_0.rst
diff --git a/docs/source/operations/projections/adams_ws2.rst b/docs/source/operations/projections/adams_ws2.rst
new file mode 100644
index 00000000..2ba6ee88
--- /dev/null
+++ b/docs/source/operations/projections/adams_ws2.rst
@@ -0,0 +1,42 @@
+.. _adams_ws2:
+
+********************************************************************************
+Adams World in a Square II
+********************************************************************************
+
++---------------------+----------------------------------------------------------+
+| **Classification**  | Miscellaneous                                            |
++---------------------+----------------------------------------------------------+
+| **Available forms** | Forward spherical projection                             |
++---------------------+----------------------------------------------------------+
+| **Defined area**    | Global                                                   |
++---------------------+----------------------------------------------------------+
+| **Alias**           | adams_ws2                                                |
++---------------------+----------------------------------------------------------+
+| **Domain**          | 2D                                                       |
++---------------------+----------------------------------------------------------+
+| **Input type**      | Geodetic coordinates                                     |
++---------------------+----------------------------------------------------------+
+| **Output type**     | Projected coordinates                                    |
++---------------------+----------------------------------------------------------+
+
+
+.. figure:: ./images/adams_ws2.png
+   :width: 500 px
+   :align: center
+   :alt:   Adams World in a Square II
+
+   proj-string: ``+proj=adams_ws2``
+
+Parameters
+################################################################################
+
+.. note:: All parameters are optional.
+
+.. include:: ../options/lon_0.rst
+
+.. include:: ../options/R.rst
+
+.. include:: ../options/x_0.rst
+
+.. include:: ../options/y_0.rst
diff --git a/docs/source/operations/projections/guyou.rst b/docs/source/operations/projections/guyou.rst
new file mode 100644
index 00000000..89d455be
--- /dev/null
+++ b/docs/source/operations/projections/guyou.rst
@@ -0,0 +1,42 @@
+.. _guyou:
+
+********************************************************************************
+Guyou
+********************************************************************************
+
++---------------------+----------------------------------------------------------+
+| **Classification**  | Miscellaneous                                            |
++---------------------+----------------------------------------------------------+
+| **Available forms** | Forward spherical projection                             |
++---------------------+----------------------------------------------------------+
+| **Defined area**    | Global                                                   |
++---------------------+----------------------------------------------------------+
+| **Alias**           | guyou                                                    |
++---------------------+----------------------------------------------------------+
+| **Domain**          | 2D                                                       |
++---------------------+----------------------------------------------------------+
+| **Input type**      | Geodetic coordinates                                     |
++---------------------+----------------------------------------------------------+
+| **Output type**     | Projected coordinates                                    |
++---------------------+----------------------------------------------------------+
+
+
+.. figure:: ./images/guyou.png
+   :width: 500 px
+   :align: center
+   :alt:   Guyou
+
+   proj-string: ``+proj=guyou``
+
+Parameters
+################################################################################
+
+.. note:: All parameters are optional.
+
+.. include:: ../options/lon_0.rst
+
+.. include:: ../options/R.rst
+
+.. include:: ../options/x_0.rst
+
+.. include:: ../options/y_0.rst
diff --git a/docs/source/operations/projections/images/adams_hemi.png b/docs/source/operations/projections/images/adams_hemi.png
new file mode 100644
index 00000000..7bfce0e5
--- /dev/null
+++ b/docs/source/operations/projections/images/adams_hemi.png
diff --git a/docs/source/operations/projections/images/adams_ws1.png b/docs/source/operations/projections/images/adams_ws1.png
new file mode 100644
index 00000000..5ec2917b
--- /dev/null
+++ b/docs/source/operations/projections/images/adams_ws1.png
diff --git a/docs/source/operations/projections/images/adams_ws2.png b/docs/source/operations/projections/images/adams_ws2.png
new file mode 100644
index 00000000..b133c084
--- /dev/null
+++ b/docs/source/operations/projections/images/adams_ws2.png
diff --git a/docs/source/operations/projections/images/guyou.png b/docs/source/operations/projections/images/guyou.png
new file mode 100644
index 00000000..08cb3df4
--- /dev/null
+++ b/docs/source/operations/projections/images/guyou.png
diff --git a/docs/source/operations/projections/images/peirce_q.png b/docs/source/operations/projections/images/peirce_q.png
new file mode 100644
index 00000000..9e5fe446
--- /dev/null
+++ b/docs/source/operations/projections/images/peirce_q.png
diff --git a/docs/source/operations/projections/index.rst b/docs/source/operations/projections/index.rst
index c5b249c9..fc2ef9fd 100644
--- a/docs/source/operations/projections/index.rst
+++ b/docs/source/operations/projections/index.rst
@@ -12,6 +12,9 @@ Projections map the spherical 3D space to a flat 2D space.
 .. toctree::
    :maxdepth: 1
 
+   adams_hemi
+   adams_ws1
+   adams_ws2
    aea
    aeqd
    airy
@@ -55,6 +58,7 @@ Projections map the spherical 3D space to a flat 2D space.
    goode
    gs48
    gs50
+   guyou
    hammer
    hatano
    healpix
@@ -104,6 +108,7 @@ Projections map the spherical 3D space to a flat 2D space.
    ortho
    patterson
    pconic
+   peirce_q
    poly
    putp1
    putp2
diff --git a/docs/source/operations/projections/peirce_q.rst b/docs/source/operations/projections/peirce_q.rst
new file mode 100644
index 00000000..86445ea1
--- /dev/null
+++ b/docs/source/operations/projections/peirce_q.rst
@@ -0,0 +1,42 @@
+.. _peirce_q:
+
+********************************************************************************
+Peirce Quincuncial
+********************************************************************************
+
++---------------------+----------------------------------------------------------+
+| **Classification**  | Miscellaneous                                            |
++---------------------+----------------------------------------------------------+
+| **Available forms** | Forward spherical projection                             |
++---------------------+----------------------------------------------------------+
+| **Defined area**    | Global                                                   |
++---------------------+----------------------------------------------------------+
+| **Alias**           | peirce_q                                                 |
++---------------------+----------------------------------------------------------+
+| **Domain**          | 2D                                                       |
++---------------------+----------------------------------------------------------+
+| **Input type**      | Geodetic coordinates                                     |
++---------------------+----------------------------------------------------------+
+| **Output type**     | Projected coordinates                                    |
++---------------------+----------------------------------------------------------+
+
+
+.. figure:: ./images/peirce_q.png
+   :width: 500 px
+   :align: center
+   :alt:   Peirce Quincuncial
+
+   proj-string: ``+proj=peirce_q``
+
+Parameters
+################################################################################
+
+.. note:: All parameters are optional.
+
+.. include:: ../options/lon_0.rst
+
+.. include:: ../options/R.rst
+
+.. include:: ../options/x_0.rst
+
+.. include:: ../options/y_0.rst