libproj: hints for CSV files from GDAL, see http://trac.osgeo.org/grass/ticket/2456

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@62321 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/proj/README.txt

@@ -4,3 +4,5 @@ The EPGS DB is transformed into suitable CSV data for GDAL/PROJ
 according to this procedure:
 http://svn.osgeo.org/metacrs/geotiff/trunk/libgeotiff/csv/README
 
+alternative:
+ls `gdal-config --datadir`