Blender Git Loki

Initial refactor of interface widget architecture

Initial refactor of interface widget architecture towards the following goals:
* Widget Draw Styles (see T45025 - heavily overlaps with this)
* Isolating widget code to make it more future proof
* Adding callback based widgets handling module (currently handled in interface_handler.c)

Adds the following folders/files:
interface/widgets/
interface/widgets/widgets.c
interface/widgets/widgets.h
interface/widgets/widgets_draw/
interface/widgets/widgets_draw/drawstyle_classic.c
interface/widgets/widgets_draw/widgets_draw.c
interface/widgets/widgets_draw/widgets_draw_intern.h

Not sure if editors/interface/ is the right place for this, but depends on some further decisions.

Tweak 'a' placement in splash

BGE: Fix T45267 Lib load without material caching.

Blender 2.75 release: We're now at 'a' release

Cycles: Add an option to force disable all OpenCL devices

This way it's possible to disable OpenCL devices for AMD devices
which are considered whitelisted.

Fix: Keyframe indicators for NLA Strip properties fails if the AnimData has an active action

Fix T45331, a bevel regression for 2.75.

Got bad results when two beveled edges form straight line
and there are two or more unbeveled edges attached to either
side of the connecting vertex.

Fix T45237: Dither does not work

Fix T45290: Selecting passes in image editor does no longer work

This issue was introduced with the wrong fix I committed for dither (rB56ca7f34)
Which also means T45237 has to be re-open

Correct vert-slide helper-line scale

Was invalid in perspective view

Fix T45281: IOR Value Slider with "Ctrl" modifier does not increment as intended.

Looks like a typo in rB1b8069bd?

Multi-View UI: convergence is only useless for the parallel camera (toe-in still uses it)

Fix vertex slide regression w/ rotated objects

This could only be done with certain rotations.

Fix T45269: Blender 2.75 crashes when I run my the game

Velocity clamping on static objects caused a crash.

Correct --help message

GPencil Sculpt: Redraw the view on mousemove even if none of the strokes was affected

The active viewport needs to get redrawn, or else the brush circle will not move
when "selection mask" is enabled and the user is trying to paint over non-selected
areas.

GPencil Sculpt: MMB can now be used for viewport manipulations while the sculpt operator is active

CMake support

GPencil Sculpt: Code Cleanup

* Removed inlined math in favour of mathlib functions
* Simplified arguments to some functions/callbacks by reusing passsed-in coords
(as vectors/arrays instead of as separate values)

Gooseberry: Hopefully fix compilation of BGE stubs