GPKG: restore saner behaviour for Delete() method, but fix GDALDriver::Create()/CreateCopy() so that APPEND_SUBDATASET=YES creation option can be used

git-svn-id: https://svn.osgeo.org/gdal/trunk@28106 f0d54148-0727-0410-94bb-9a71ac55c965
gdalwarp: check return code of GDALSetProjection() and GDALSetGeoTransform()

git-svn-id: https://svn.osgeo.org/gdal/trunk@28107 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_vc12