FIX: when they are zero, Siemens scanners apparently do not write positions


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5347 42a5c34f-2066-0410-bec5-ba365beb4995
CHG: bump version to 3.2.1


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5349 42a5c34f-2066-0410-bec5-ba365beb4995