Changes:
- Enabled  snap angle for rotation manipulator.
- Enumerate dxgi outputs during D3D device creation (for debugging).
- minor cleanups
- Skinning: Prevent skin service from modifying background color of view controls.
  There is a setting in the preferences for that.
- Added default value to few DesignView settings. So they can be reseted using preferences dialog.
- HistoryLister improvements:
  -- Added < Clean State > as first item to allow undoing first command.
  -- Use virtual mode instead storing items locally.
  -- Removed Max command count (it is no longer needed).