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.

7 files changed, 34 insertions, 11 deletions

diff --git a/test/cli/Makefile.am b/test/cli/Makefile.am
index 33878743..417ec137 100644
--- a/test/cli/Makefile.am
+++ b/test/cli/Makefile.am
@@ -29,7 +29,7 @@ EXTRA_DIST = pj_out27.dist pj_out83.dist td_out.dist \
 		CMakeLists.txt
 
 testprojinfo-check:
-	PROJ_LIB=$(PROJ_LIB) $(TESTPROJINFO) $(PROJINFOEXE)
+	PROJ_SKIP_READ_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTPROJINFO) $(PROJINFOEXE)
 
 test27-check:
 	$(TEST27) $(PROJEXE)
@@ -41,24 +41,24 @@ testproj-check:
 	$(TESTPROJ) $(PROJEXE)
 
 testvarious-check:
-	PROJ_LIB=$(PROJ_LIB) $(TESTVARIOUS) $(CS2CSEXE)
+	PROJ_SKIP_READ_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTVARIOUS) $(CS2CSEXE)
 
 testdatumfile-check:
 	@if [ -f $(PROJ_LIB)/conus -a -f $(PROJ_LIB)/ntv1_can.dat -a -f $(PROJ_LIB)/MD -a -f $(PROJ_LIB)/ntf_r93.gsb -a -f $(PROJ_LIB)/egm96_15.gtx ]; then \
-	  PROJ_LIB=$(PROJ_LIB) $(TESTDATUMFILE) $(CS2CSEXE) ; \
+	  PROJ_SKIP_READ_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTDATUMFILE) $(CS2CSEXE) ; \
 	fi
 
 testign-check:
 	@if [ -f $(PROJ_LIB)/ntf_r93.gsb ] ; then \
-	  PROJ_LIB=$(PROJ_LIB) $(TESTIGN) $(CS2CSEXE) ; \
+	  PROJ_SKIP_READ_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTIGN) $(CS2CSEXE) ; \
 	fi
 
 testntv2-check:
 	@if [ -f $(PROJ_LIB)/ntv2_0.gsb -a -f $(PROJ_LIB)/conus -a -f $(PROJ_LIB)/ntv1_can.dat ] ; then \
-	  PROJ_LIB=$(PROJ_LIB) $(TESTNTV2) $(CS2CSEXE) ; \
+	  PROJ_SKIP_READ_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTNTV2) $(CS2CSEXE) ; \
 	fi
 
 testcct-check:
-	PROJ_LIB=$(PROJ_LIB) $(TESTCCT) $(CCTEXE)
+	PROJ_SKIP_READ_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTCCT) $(CCTEXE)
 
 check-local: testprojinfo-check test27-check test83-check testproj-check testvarious-check testdatumfile-check testign-check testntv2-check testcct-check
diff --git a/test/cli/ntv2_out.dist b/test/cli/ntv2_out.dist
index 531db7be..d90fdc37 100644
--- a/test/cli/ntv2_out.dist
+++ b/test/cli/ntv2_out.dist
@@ -13,6 +13,14 @@ Try with NTv2 and NTv1 together ... falls back to NTv1
 Switching between NTv2 subgrids
 -112.5839956 49.4914451 0	-112.58307487	49.49145197 0.00000000
 ##############################################################
+Interpolating very close (and sometimes a bit outside) to the edges a NTv2 subgrid (#209)
+-115.58333333 51.25000000 0	-115.58228512	51.24997866 0.00000000
+-115.58333333 51.25000010 0	-115.58228512	51.24997876 0.00000000
+-115.58333334 51.25000000 0	-115.58228513	51.24997866 0.00000000
+-115.49166667 51.07500000 0	-115.49062909	51.07497666 0.00000000
+-115.49166668 51.07500000 0	-115.49062910	51.07497666 0.00000000
+-115.49166667 51.07499990 0	-115.49062909	51.07497656 0.00000000
+##############################################################
 Attempt first with ntv2_0.gsb and then conus
 -111.5 45.26	-111.50079772	45.25992835 0.00000000
 ##############################################################
diff --git a/test/cli/td_out.dist b/test/cli/td_out.dist
index 478a0d84..cf4b8d73 100644
--- a/test/cli/td_out.dist
+++ b/test/cli/td_out.dist
@@ -21,7 +21,7 @@ edge or even a wee bit outside (#141).
 -5.5001 52.0	-5.500100000000	52.000000000000 0.000000000000
 -5.5 52.0	-5.498893534472	52.000109529716 0.000000000000
 -5.5000000000001 52.0000000000001	-5.498893534472	52.000109529717 0.000000000000
--5.4999 51.9999	-5.498793541695	52.000009529743 0.000000000000
+-5.4999 51.9999	-5.498793593803	52.000009531513 0.000000000000
 -5.5001 52.0	-5.500100000000	52.000000000000 0.000000000000
 ##############################################################
 NAD27 -> NAD83: 1st through ntv1 or ntv2, 2nd through conus
diff --git a/test/cli/test27 b/test/cli/test27
index bfc1cb0a..5825ed80 100755
--- a/test/cli/test27
+++ b/test/cli/test27
@@ -34,7 +34,7 @@ echo "Running ${0} using ${EXE}:"
 echo "============================================"
 
 OUT=proj_out27
-INIT_FILE=${PROJ_LIB}/nad27
+INIT_FILE=nad27
 #
 echo "doing tests into file ${OUT}, please wait"
 #
diff --git a/test/cli/test83 b/test/cli/test83
index cfb1365e..8c1293d0 100755
--- a/test/cli/test83
+++ b/test/cli/test83
@@ -35,7 +35,7 @@ echo "Running ${0} using ${EXE}:"
 echo "============================================"
 
 OUT=proj_out83
-INIT_FILE=${PROJ_LIB}/nad83
+INIT_FILE=nad83
 #
 echo "doing tests into file ${OUT}, please wait"
 #
diff --git a/test/cli/testdatumfile b/test/cli/testdatumfile
index e4b9ea2d..16e4bbc3 100755
--- a/test/cli/testdatumfile
+++ b/test/cli/testdatumfile
@@ -27,7 +27,11 @@ echo "Running ${0} using ${EXE}:"
 echo "============================================"
 
 mkdir "dir with \" space"
-cp ${PROJ_LIB}/conus "dir with \" space/myconus"
+if test -f "${PROJ_LIB}/conus"; then
+    cp "${PROJ_LIB}/conus" "dir with \" space/myconus"
+else
+    cp "`dirname $0`/../../data/conus" "dir with \" space/myconus"
+fi
 
 OUT=td_out
 #EXE=../src/cs2cs
diff --git a/test/cli/testntv2 b/test/cli/testntv2
index 72a0f9a2..44ccac1e 100755
--- a/test/cli/testntv2
+++ b/test/cli/testntv2
@@ -61,11 +61,22 @@ $EXE +proj=latlong +datum=NAD83 +to +proj=latlong +ellps=clrk66 +nadgrids=ntv2_0
 EOF
 
 echo "##############################################################" >> ${OUT}
+echo "Interpolating very close (and sometimes a bit outside) to the edges a NTv2 subgrid (#209)" >> ${OUT}
+$EXE +proj=latlong +datum=NAD83 +to +proj=latlong +ellps=clrk66 +nadgrids=ntv2_0.gsb -E -d 8 >>${OUT} <<EOF
+-115.58333333 51.25000000 0
+-115.58333333 51.25000010 0
+-115.58333334 51.25000000 0
+-115.49166667 51.07500000 0
+-115.49166668 51.07500000 0
+-115.49166667 51.07499990 0
+EOF
+
+echo "##############################################################" >> ${OUT}
 echo Attempt first with ntv2_0.gsb and then conus >> ${OUT}
 $EXE +proj=longlat +datum=NAD27 +to +proj=longlat +datum=WGS84 -E -d 8 >>${OUT} <<EOF
 -111.5 45.26
 EOF
-#
+
 echo "##############################################################" >> ${OUT}
 echo "NAD27 -> NAD83: 1st through ntv2, 2nd through conus" >> ${OUT}
 #