#6 Using mouse-tracking loop approach to handle dragging and mouse up. First seemingly working version
#6 Added a comment for mouse-track loop approach and moved private methods down
#6 deleted unused instance variable
#6 reconciling mouse-track loop and drag and drop session
#6 -mouseDown: invocations in tests enters infinite loop, disabled. Fix them!
#6 fixed some tests and deleted some tests that do not make much sense
#6 incremented the version to 0.0.12 (13)
#6 adapted mind map view event tests
#6 fixed the window dragging bug