instead of drawing everything again, in all windows, it restricts to
the active and previous active object. when there are more objects to
be redrawn, it does a normal swapbuffers.
Result is it all redraws & selects a lot faster in complex scenes
* Little fix in "BallTable" routine when moving mouse vertical out of
the 3d window.
In fact, I made it working different, much more cooler!
-------The BallTable Method TM (patent pending)------------
This is a hybrid of the old turntable method (a virtual camara that rotates
around a table) and the trackball method. Mouse moving horizontal, gives
the turntable effect, but with vertical movement it works like a trackball.
So, vertically moving in the middle of the window exactly mimics old
turntable method, moving vertically in the window edge gives a 'twist'
rotation.
Try the turntable for fun! (is in user settings menu)
