Extracting paint operations from KisPainter

[Casper Boemann]

> Ultimately, my goal is to separate the ui for tools (freehand, line,
> ellipse, etc.), 'brushes' (brush, pen, airbrush, eraser) and brush shapes
> (the current Gimp brushes). Perhaps better names would be 'actions',
> 'tools' and 'brushes'. It's done this way in Corel Painter, and it allows
> easy extension with new paint op types.
YES, just what I'm dreaming of.

best regards
Casper Boemann