Blender Git Loki

Replace low-level HMD check with higher level API call

Cycles: Tweak feature pass heuristic

Make HMD window a proper 'restricted' window

A restricted window is a new concept that doesn't allow changing the screen of a window in any way. This way we can ensure the HMD window is only used for displaying the 3D View, so users can't accidentally change it without knowing how to get back. This also fixes some issues we had when using temp screens like they're used for UserPrefs.
Fixes:
* Could open toolbar/properties in HMD view
* HMD window used when opening UserPrefs through menu/shortcut
* Could easily change editor to non-3D-View

Cycles: Fix optimization includes

Fix double freeing of OpenVDB data from dangling pointers in device data.

Move HMD view shading option to window manager level

Was a bit ugly to have this in scene level, window manager isn't perfect either, but prefer it there.

Move HMD panel into 3D View properties

Still not a really perfect place since this is global, but can't think of a better one. More options will be added later on, so worth having an own panel.

Cycles: Rename collaborative denoising option

Merge remote-tracking branch 'origin/master' into soc-2016-cycles_denoising

Move registration of volumes from attributes out of the smoke sim logic.

This bit of code will be the same for every potential source of volumetric
data.

Cycles: Cache NLM weights

Cleanup of Blender sync code for OpenVDB volume attributes.

Besides removing some debug printing lines, the code should also become
easier to adapt to alternative sources of volume data beside the smoke sim.

Cycles: Rename Denoising DNA flags for clarity

Cycles: Add options for NLM and collaborative filtering

Cycles: Fix Collaborative CUDA WLR denoising

Use tri-linear ("box") interpolation for OpenVDB grids rather than nearest point sampling.

Cycles shading options contain a setting for tri-cubic sampling as well, but this
is not supported in OpenVDB by default (only tri-quadratic). Cubic sampling appears
a bit pointless anyway, compared to the ability to add actual geometric detail.

no need to use two cells for border of smoke domain

Merge branch 'master' into asset-engine

Conflicts:
source/blender/blenkernel/BKE_library.h
source/blender/blenkernel/intern/library_remap.c

Merge branch 'master' into openvdb

Cycles: Fix CUDA compilation with NLM