Merge branch 'gooseberry' into temp_motionpaths

Conflicts:
source/blender/blenkernel/intern/object.c

Super hacky hack (not for master for sure) to stop blender for crashing
with scene audio recursion in mattieu's gooseberry edit in sequencer.

Will probably cause something else to explode but let's just guard
against this in the audio lib for now.

Sequencer:

Add option to ommit strip name and info display.

Gooseberry: Use more proper flag for psys reconstruction after memory optimization

Gooseberry: Fix for flickering grass

The issue was caused by memory optimization marking particle system to recalc,
and because of the way how particle flags works it was possible that it'll
cause particle's re-distribution. Now this memory optimization will act the
same as loading the file.

Would need to review if this fix is to go to master/cycles_memory branches
but for now it'll be cool to figure out what to do with the farm.

More cosmetic stuff for the play button

Draw outer ring with quad strip instead of line
(line width would vary across the ring)

Small cheat for attract tool:

Draw overdrop on top of post-draw call back.

Particles: Avoid bad memory access when calculating child weight

Not sure it's totally correct solution, but it's better than giving
unpredictable results.

Center the play gisom triangle more correctly.

Reset frame when stopping playing.

Add play gismos to collapsed image sequences. When clicking repeatedly
on the sequence they are toggled between play-pause.

Disable file collapse when user cancels after an operator.

Now file open operator also sets a temporary flag for collapse. This
allows the user to configure the option to always collapse files and the
editor will remember the setting and not reset it back after finishing a
collapsed file open.

Never collapse directories

Animation support for collapsed image sequences.

Selected animation sequences will play back their thumbnails now.

We'll probably need a way to scrub here, will investigate that next.

Gooseberry: Previous commit broke compilation of debug builds

Merge branch 'cycles_memory_experiments' into gooseberry

Conflicts:
intern/cycles/blender/blender_object.cpp
intern/cycles/blender/blender_sync.h

Gooseberry: Fix compilation error with strict compiler flags

Yet another weekly issue squashed, player did not display indicator with
image sequences.

Simple matter of storing the frame for image sequences too.

Sort files in collapsed sequences by frame number.

Now getting an "animation" preview should be pretty easy.

Cycles: Merge density and color volume attributes if they both requested

This way we store quite reasonable amount of memory (density is stored as RGBA
textures, which ends up in gigabytes of RAM for hires smoke sims).

It's not really pretty implementation and we'll really need to support textures
with 1 and 3 channels instead of doing such packing, but we need to be able to
render some files here.