LIBKML: take into account feature Id on CreateFeature() on a update document; add kml_generate_test_files.py script to test files that can be used to exercice the points tested by the OGC KML 2.2 – Abstract Test Suite

git-svn-id: https://svn.osgeo.org/gdal/trunk@27115 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_travis_macosx