Paint system

* Add unified color settings to brush menus.
* Add notifier on fill tool from drag and drop to refresh icons
Minor polishing, add UV layer selection in image projection painting
mode.
Another minor correction, use "Mask" instead of "Stencil" so users can
correlate the panel to the mask tool.
Last minute artist feedback tweak: Fill tool should not use masking
apart from stencil(texture) and face masks.
Py Template: Set the active object in batch export

Some exporters (mdd for example), only use the active object
initial similar script
Basic select similar starting point
Basic working version
Minor improvements
Works quite well now
remove passes, minor improvements
Fix for finding  initial region
enable rehash
correct levels search
add region match files
remove faces_done, no need