Correct assert for RNA IDProps
Fix T39563: Tiny unit-display problem in constraint panels.

There is no good solution here, since RNA props can only have one type/unit.
Tried to find the less worse one - have different RNA props for same DNA value
(a bit like the angle/length for camera lens).

Also fixed two other issues with Transform conctraint:
* Angle were still in degrees (yes, another backward-compatibility breacking).
* Scale was absolute, unlike loc/rot.

Also cleaned up a bit the code, replaced some magic numbers by proper enums, ...
Fix T39562: Properties panel Pinning is broken

'scene' was simply not handled in button context.
Fix T39623: deleting an object crashes
Code cleanup: use parens around multi-line defines.
Code cleanup: make the source G rated again.
OpenCL + AMD adapt kernel to newer driver
OpenCL Change opencl_assert to be more like cuda assert where possible.
added some extra warnings and feedback if things go wrong
Fix own broken rB95b25e7333c4 (crash on any undo op :/).

Issue here was that buttons_texture_context_compute() was getting scene from (button-customized) context,
before the button paths (and hence, context) had been updated. So after an undo, it was getting an invalid
(freed by undo) scene pointer.

Now update BCONTEXT_SCENE path before calling buttons_texture_context_compute().
Color pickers:

* Code Cleanup
* Fix some more color correction cases that were left unattended. (NDOF,
resetting the operation in circle pickers)
Fix own rB8714ae09f894: Forgot to handle bone constraints in versionning code!
Weekly UI messages fixes...
Fix T39626 Matcaps not working in edit mode.

Set a while color before the draw call. This will be ineffective in GLSL
but will affect matcaps.
Enable openmp in MinGW-w64
Fix T39635: Crash convening curve to mesh
Code cleanup: remove paranoid NULL check
Matcaps.

Instead of setting color every time, just set it on material enable.
Handles all cases of surfaces. Thanks to Campbell for pointing out!
Mempool: delay allocating an initial chunk, its not always used
BMesh: minor speedup, avoid calloc+assign, assign all members instead
BMesh: bmesh_sfme now initializes the copy