MITAB: refactor import/export of MIF coordsys to use the TAB code; take into account MITAB_BOUNDS_FILE to add Bounds to the CoordSys string

git-svn-id: https://svn.osgeo.org/gdal/trunk@28020 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_mingw