Blender Git Loki

projection painting clone tool - gives a similar work flow to cloning in the gimp, Ctrl+Click to set the cursor source, then paint from this location.

todo...
* pixel interpolation.
* clone option can currently only be set from the image paint panel.
* only initialize clone pixels under the mouse.
* overlap between source/target while painting could cause problems. need to look into this.

also fixed some cashes in painting normally.