The `OGRGeometry.coord_dim` property may now be set; implemented a work-around...

The `OGRGeometry.coord_dim` property may now be set; implemented a work-around for an OGR bug that changed geometries to 3D after transformation.  Refs #11433.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@11628 bcc190cf-cafb-0310-a4f2-bffc1f526a37