use portable formatter

git-svn-id: https://svn.osgeo.org/gdal/trunk@27067 f0d54148-0727-0410-94bb-9a71ac55c965
also accept mingw formatting

git-svn-id: https://svn.osgeo.org/gdal/trunk@27068 f0d54148-0727-0410-94bb-9a71ac55c965