ADD: API for getting global affine matrix from poly xform


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5161 42a5c34f-2066-0410-bec5-ba365beb4995
ADD: some more bits about global affine and global scale


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5162 42a5c34f-2066-0410-bec5-ba365beb4995