change hermannskogel to using better transformation (#207)

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk/proj@2398 4e78687f-474d-0410-85f9-8d5e500ac6b2
add MGI datum check

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk/proj@2399 4e78687f-474d-0410-85f9-8d5e500ac6b2