#35 dicom paths in mrml files need rework

[Steve Pieper]

There are two problems that should probably be fixed at
once:

(1) spaces in dicom filenames aren't parsed correctly
(probably an escape character needs to be embeded in
the filenames).

(2) if the directory containing the dicom files has an
extension (e.g. .ACQ) it gets stripped before the file
gets saved.