BUG: Fixed saving of inverted linear transforms (conversion to ITK sense was missed for inverse transforms)

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23427 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Fixed crash on scene close when the Transforms module is active

Units module triggered an update in the Transforms module GUI after the current transform node has been already deleted.
Use a weak pointer to make sure no dangling pointers are accidentally used.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23428 3bd1e089-480b-0410-8dfb-8563597acbee