Blender Git Loki

Remove jitter from brush cache tests it is also unneeded.

Make palette sampling more stable. It was possible to sample too many
palette colors just by hovering the pen over the screen.

More cruft removal and cleanup of 2d paint cache invalidation.

Refactoring:

Separate mask texture and color texture sampling. Old code was
exceedingly convoluted and hard to follow. Now the two texture slots
handle updating independently. There may be some updating errors
but preliminary testing seems OK.

TODO, possible now at last: Manage partial update
for mask textures just like color textures.

Deduplicate some gradient evaluation code

Fix: Fill tool in projection painting could still use secondary color

Merge branch 'master' into soc-2013-paint

move layers to their own panel

merge with master 19f7f9afab1b36ca

fix merge conflict for blenderplayer

fix error in last merge

Merge branch 'master' into soc-2013-paint

merge with master 054094f5827f3

merge with master a930fb154f47a7473848254ad0b0b83c9edd1850

Make mode stroke enum normal if operator is using Curve or Polyline
mode. It made it confusing because users used ctrl-click to add extra
points, often inverting the stroke.

merge with trunk -r 61215

Fix anchored and drag dot strokes not being undoable after last commit
to undo tiles. Not really nice but it works for now.

merge with trunk 60884

Simplify undo pushing for projection painting.

* Do not compare image pixels at end of stroke, it causes a great
stutter at the end of painting on large images (4096x4096 in my test
case). In any case tiles have been pushed already for such images.

* Only add tile if pixel passes the mask test. Previous approach could
add tiles even for clipped pixels.

merge with trunk -r60676

merge with trunk -r60675, should solve some ocio compilation issues.