WFS 2.0: be a good citizen and send TYPENAMES (with a S) for GetFeature request (but still TYPENAME for DescribeFeatureType)

git-svn-id: https://svn.osgeo.org/gdal/trunk@26548 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_travis_macosx