Switch schwehr@gmail.com to schwehr@google.com by request of Google, my employer

git-svn-id: https://svn.osgeo.org/gdal/trunk@27753 f0d54148-0727-0410-94bb-9a71ac55c965
Implement SPATIAL_INDEX layer creation option for MSSQL. (#5563)

git-svn-id: https://svn.osgeo.org/gdal/trunk@27754 f0d54148-0727-0410-94bb-9a71ac55c965
More CPL_UNUSED (#5414)

git-svn-id: https://svn.osgeo.org/gdal/trunk@27755 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_vc12