Revert "ResizableFrame: Simplify logic for resize/move action."

To make this branch compatible with l3u's branch...
This reverts commit 6a535465cb6b7395a83d92b7d7bcc178d20c54e3.
Adapted the coding style of ResizableFrame.
ResizableFrame: Simplify logic for resize/move action.

Conflicts:
	AnnotationDialog/ResizableFrame.cpp
	AnnotationDialog/ResizableFrame.h
Restricted the area drag/resize to the image preview geometry. The top and left scale is not as robust as it should be yet ...
Fixed the top and left resize so that the height and width don't change anymore.
Started handling "inversion". When moving the mouse fast, inversion from top to bottom and from left to right is not handled correctly yet (the frame moves when it should not).
Fixed inversion. Quite easy ;-) No need for additional variables, there's dragStartGeometry already.