New Scrollbars for Rotations

* Like the Google Picasa Program, the scrollbar stays in the center.
* When drug, the rotations for that dim. continuously increment.
* Rotation increments are prop. to scroll's distance from the center.
* You can increment rotations 1 deg. at a time with the scroll arrows.
* On screen rotations still sync with UI rotations.
* 45 degree lock works with this new feature as expected.
Rotate reset fix