Blender Git Loki

Projection Painting, merge from branch

Additions/Features...
- Painting onto multiple images at once.
- Clone with an offset similar to the gimp, also an option to clone between UV layers, (not both offset and between layers atm)
- Stencil layer, similar to The Gimp's quickmask.
- Face mask mode - (painting onto only selected faces).
- Texture brushes (so image and texture-node brushes too)
- Seam bleed so you don't see gaps when painting over UV seams (new option set in the panit panel)
- Occlusion (only point onto the first face under the paintbrush, can also be used for masking out parts of the model to paint onto) - (new option set in the paint panel)
- Muti-threaded, each thread operates on its own bucket.
- Support partial updates to speedup OpenGL texture refreshing.
- Support tile based multiple undo's
- Support float image buffers.
- Backface culling (new option set in the paint panel)
- All color blending modes - Add/Multiply.. etc.
- Airbrush rate. (used to be broken)
- Improve the way paint is mixed when painting, so painting with 0.2 alpha will not accumulate above 0.2 alpha on the image as you paint.
- Option to use normals to fade out strokes on the edge of a surface to avoid ugly edges. (same as Vertex Paints "Normal" option)

Known Problems
- Not directly related to painting but changes in selection flags are not updated on the final derived mesh.
- Smear tool has some distortion when in perspective mode.
- While in perspective view any faces with 1 vert behind the viewpoint, will be completely ignored.
- Painting can be initially slow while buckets are being initialized, a number of solutions exist.
- Size 1 brushes don't work yet.
- When painting onto large faces its still possible to get artifacts.
- Spatial optimizations are needed to skip occluded faces and test pixel occlusion. (will look into using blenders BVH )