Merge RFC4 (#1865)

This commit is the result of the squashing of rfc4_dev branch in a single
commit. It implements mostly RFC 4 related work.

* Grid handling:
  - remove obsolete and presumably unfinished implementation of grid catalog functionality
  - all grid functionality is in grids.cpp/.hpp
  - vertical and horizontal grid shift: rework to no longer load whole grid into memory
  - remove hgrids and vgrids member from PJ structure, and store them in hgridshift/vgridshift/deformation structures
  - build systems: add optional libtiff dependency. Must be explicitly disabled if not desired
  - add support for horizontal and vertical grids in GeoTIFF, if libtiff is available
  - add GenericShiftGridSet and GenericShiftGrid classes, relying on TIFF grids, that can be used for generic purpose grid-based adjustment
  - add a +proj=xyzgridshift method to perform geocentric translation by grid. Used for French NTF to RGF93 transformation using gr3df97a.tif grid
  - deformation: add support for +grids= for GeoTIFF grids
  - horizontal grid shift: fix failures on points slightly outside a subgrid (fixes #209)

* File management:
  - add a filemanager.cpp/.hpp to deal with file related work
  - test for legacy proj_api.h fileapi
  - proj.h: add proj_context_set_fileapi() and proj_context_set_sqlite3_vfs_name() (fixes #866)
  - add capability to read resource files from the user writable directory

* Network access:
  - build systems: add optional curl dependency
  - add a curl-based default implementation for network related functionality
  - proj.h: add C API to control network functionality, and optionaly provide network callbacks
  - add data/proj.ini with default settings
  - add a SQLite3 local cache of downloaded chunks
  - add proj_is_download_needed() and proj_download_file()

* Use Win32 Unicode APIs and expect all strings to be UTF-8 (fixes #1765)
  For backward compatibility, if PROJ_LIB content is found to be not UTF-8 or
  pointing to a non existing directory, then an attempt at interpretating it
  in the ANSI page encoding is done.
  proj_context_set_search_paths() now assumes strings to be in UTF-8, and
  functions returning paths will also return values in UTF-8.

1 files changed, 34 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9d108135..e2264b25 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -83,6 +83,7 @@ elseif("${CMAKE_C_COMPILER_ID}" STREQUAL "Intel")
     set(PROJ_CXX_WARN_FLAGS -Wall)
   endif()
 endif()
+
 set(PROJ_C_WARN_FLAGS "${PROJ_C_WARN_FLAGS}"
   CACHE STRING "C flags used to compile PROJ targets")
 set(PROJ_CXX_WARN_FLAGS "${PROJ_CXX_WARN_FLAGS}"
@@ -134,6 +135,39 @@ IF("${SQLITE3_VERSION}" VERSION_LESS "3.11")
 ENDIF()
 
 ################################################################################
+# Check for libtiff
+################################################################################
+
+option(DISABLE_TIFF "Disable TIFF support" OFF)
+mark_as_advanced(DISABLE_TIFF)
+if(DISABLE_TIFF)
+  message(WARNING "TIFF support has been disabled and will result in the inability to read some grids")
+else()
+  find_package(TIFF REQUIRED)
+  if(TIFF_FOUND)
+    boost_report_value(TIFF_FOUND)
+  else()
+    message(SEND_ERROR "libtiff dependency not found!")
+  endif()
+  add_definitions(-DTIFF_ENABLED)
+endif()
+
+################################################################################
+# Check for curl
+################################################################################
+
+option(ENABLE_CURL "Enable Curl support" ON)
+if(ENABLE_CURL)
+  find_package(CURL REQUIRED)
+  if(CURL_FOUND)
+    boost_report_value(CURL_FOUND)
+  else()
+    message(SEND_ERROR "curl dependency not found!")
+  endif()
+  add_definitions(-DCURL_ENABLED)
+endif()
+
+################################################################################
 # threading configuration
 ################################################################################
 set(CMAKE_THREAD_PREFER_PTHREAD TRUE)