MovePlugin will no longer try to transform the selection in MoveSelection mode when the mouse moved without any button pressed.

Backups of the selection will only be created when something actually changed (transformation matrix != identity matrix).

git-svn-id: http://www.openflipper.org/svnrepo/OpenFlipper/branches/Free@10730 383ad7c9-94d9-4d36-a494-682f7c89f535