[DISCONTINUED] Snapper

Rewritten SnapToGrid and using SetHook instead of meta hooking, it's not a bad idea but we now got a API to hook with so it's fine as well. Only issue is that the frame needs to be a child of UIParent -most frames are, some few frames are not (sneaky!)

Thanks to all the past authors that wrote SnapToGrid, that is:
Gello, JoshBorke and Iriel (anyone left uncredited -sorry!)

Note that addons that have frames that do not use OnMouseDown and OnMouseUp will not be snapp-able, I will look into this in the future and see how I can hook them too but until then we will survive aligning the addons that do use these methods.