BLender 2.76: We go 'b' series now

Don't expand toggle brush on linking

Toggle brush is more a runtime only feature, not really supposed to be used
as real ID linking as it's done for modifiers i.e.

Fix T46626: Crash generating previews

Brush.toggle_brush was allowed to be an invalid pointer,
it worked for the one operator that used it - but in general bad practice,
requiring a lookup on every access.

Ensure the pointer is kept valid now.

Fix/workaround T46622: crash w/ metas & particles

Metas are scanning all scenes duplis,
which can go into particle systems without an initialized derived-mesh.

For now just do NULL check, its not correct but real fix is not fitting well with current design.

Fix T46651: Select linked crash w/ wire seam edges

Revert "Fix T46494: Can't de-select a face w/ mixed modes"

This reverts commit 381501ab45d63abb1502656c35e01adce36e7e34.

Fix T46507: Cycles baking re-orders face

Regression in 2.76, order of tessellated vertices needs to follow MFace tessellation.

Blender 2.76a: Fix CUDA compilation on 32bit platform

BLender 2.76a: Update addons submodule

Set blender version to '2.76a'

Cleanup: quiet warning

Not cherry picked, just included for release build.

Follow up to previous commit, proper fix for T46284, incorrect Texture
shading in Texture paint mode and cycles

Revert "Fix T46284: Texture paint, wrong shading mode"

Should fix T46616 but will reintroduce T46284.
The second, original bug needs different handling

This reverts commit 904db487a7b14c31282fe0284612159a836657cd.

Fix T44231: Freestyle causes crash on render.

The reported crash was confirmed as a segmentation fault in std::sort().
The cause of the crash was traced down to a binary comparison function
that was not satisfying the so-called strict weak ordering requirements of
the C++ standard sorting function. Specifically, the comparison operator
has to return false when two objects are equivalent (i.e., comp(a, a) must
be false), but that requirement was not met.

Since the binary comparison operator in question could be a user-defined
Python function, here a safety measure is implemented in the C++ layer to
make sure the aforementioned requirement is always satisfied.

Temporary "fix" for crash when saving OpenEXR Multi-View from Image Editor

Fix T46617 File Output Node seems to save only black images into OpenEXR image data

If the node output had only one layer, it would be detected as singlelayer, and it would miss the blender exr header string

Freestyle: Fix for 'Distance from Object' modifiers without a target object.

'Distance from Object' color/alpha/thickness modifiers without a target
object were raising a run-time exception although it is not considered an
error condition.

Fix broken comment about our WM progress report for python (its not a progress bar at all).

Fix: Prevent warnings from popping up when trying to edit driver expressions from buttons

Previously, a warning was added to provide feedback to users trying to change the values
of driven properties why their edits would not have any effect on the propeerty. However,
it turned out that instead of only showing up when the user tried to increment/decrement/slide
the property's value, it was also firing everytime they were trying to edit the expression.
That however is not what we want at all!

This fix assumes that BUTTON_STATE_TEXT_EDITING is used for expression editing, and
BUTTON_STATE_NUM_EDITING (or everything else) refers to the user trying to adjust the
value normally.

Freestyle: minor speed-up by omitting the calculation of the smallest edge size.

BlenderFileLoader tries to find the smallest edge size but the computed value is not used.