Enhanced and fixed

Enhanced:
- Added feature to passive listen for the scroll by notification
- Added refresh function to allow custom background instead of just
screen grabs
- Renamed and changed type of relativeFrame, since only needed origin
- Added an experimental optimization, turned off by default

Fixed:
- Agressively use newly renamed relativeOrigin to correct the
background's scrolling. You can still set your own relativeOrigin but
the defualt is written in such a way that it is frame insensitive.