Read WKB POINT(NaN NaN) as POINT EMPTY
Refactor to expose OGRCreateFromMultiPatchPart()

git-svn-id: https://svn.osgeo.org/gdal/trunk@26735 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into isowkb
Merge branch 'isowkb' of github.com:pramsey/gdal into isowkb