CHG: detect Philips average DWI and do NOT write bVector in its XML file


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5199 42a5c34f-2066-0410-bec5-ba365beb4995
FIX: b=0 image has "valid" bVector


git-svn-id: https://www.nitrc.org/svn/cmtk/trunk@5200 42a5c34f-2066-0410-bec5-ba365beb4995