FIX: catch const exceptions


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5113 42a5c34f-2066-0410-bec5-ba365beb4995
FIX: catch exceptions resulting from matrix composition


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5114 42a5c34f-2066-0410-bec5-ba365beb4995