Point submodules to the final release tag

Branch is not really a release state!

Bugfix: Fix for crash when trying to create new action in Shape Key DopeSheet mode

When the active object had no shapekey data, trying to create a new action from the
Shape Keys mode of the DopeSheet would crash. The segfault here was a silly regression
caused by my earlier Action Stashing work.

However, the old (pre-Action Stashing) code here also wasn't that great either.
While it didn't crash, it would still silently create a new action, even if that
could not get assigned/used anywhere. To prevent both of these problems from
happening again, I've added additional null checks, as well as beefing up the poll
callback here to forbid keyframing

Fix T44077 material update fails in textured mode when VBOs are off.

The issue has been here since we changed drawing code for meshes to use
vertex arrays instead of immediate mode when VBO was off. Basically we
should now always invalidate the GPU objects regardless of the VBO
setting in the preferences.

The bug has been there since 2.73 at least, but what made it apparent
now is that new version resets preferences and as an extension the VBO
flag.

Should be included in final 2.74 release

Fix T44201: Crash Deleting Hierarchy in Outliner

Typical error using '->next' member of a freed linked list item. A bit trickier
even here, since we have some recursion...

Trivial fix for nasty crasher, safe for 2.74 imho?

Remove use_invert_vertex_group use_ prefix

To match other modifiers.

Fix T41191: Custom Loop Normals Viewport shading not updating when set from py script

Missing update tagging...

Safe for 2.74.

Fix T44137: bpy.path.is_subdir fails

`bpy.path.is_subdir("/abc/def/ghi","/abc/de")` incorrectly returned True

Fix T44149: Compositing : Node Groups do not work correctly

Input constants are to be connected before removing proxies,
otherwise node groups might give totally different result.

This is a regression and to be put into final release.

Fix T44193: Hair intersection with duplis causes flickering

It was an issue with what bounds to use for BVH node during construction.

Also corrected case when there are all 4 primitive types in the range and
also there're objects in the same range.

Fix for invalid buffer access on zero-face meshes

Fix T44186: Bezier Bevel facto mapping broken when 'start' was set to 'Resolution' and 'end' was not.

Trivial, we need totla_length in that case too.

Safe to be backported to 2.74.

Point addons to 2.74-rc4 tag

Bump splashscreen to rc4

Fix T44138: Crash in DataTransfer modifier when selecting a source with no loops.

Simply check and early return in case we have no source or destination items
(verts/edges/loops/polys) available...

Also, fix an assert in `BKE_mesh_calc_normals_poly()`, when called with no poly.

Yet another fix for crashing particles.

Fix T44133 SSAO in OpenGL rendering from orthographic camera did not
work

Safe to include in final release

Fix T44118: Rotated background image disappears

Image clipping didn't take rotation into account.

Fix for crash when using particle emission with clump/roughness curves
in a smoke sim.

This interaction between sims is totally stupid and must be recoded
entirely in some utopian future.

Fix 2 typos ( shakin' hands )