ADD: get dwell time from both Siemens and GE DICOM files


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5011 42a5c34f-2066-0410-bec5-ba365beb4995
TST: added DwellTime to XML sidecar files


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5012 42a5c34f-2066-0410-bec5-ba365beb4995
DOC


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5013 42a5c34f-2066-0410-bec5-ba365beb4995