LIBKML: implement ATC 13: check that altitudeMode == clampToGround (or clampToSeaFloor) if tesselate == 1

git-svn-id: https://svn.osgeo.org/gdal/trunk@26923 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_with_coverage