Blender Git Loki

Various cleanups.

Initial support for rendering vdb file sequences.

Cycles: add support for transforming the grid (pos, rot, scale).

This makes it easier to incorporate external VDB files in the Cycles
scene (at least in Blender).

Cleanup.

Cycles, OpenVDBManager: split routines into separate functions.

Cycles: add OpenVDBManager::delete_sampler convenience function.

Cycles: move routine to find an exiting grid slot to its own function.

Cycles: add grid memory usage to logging.

Cycles: use ccl_fetch to get the shading point position.

WIP patch for OpenVDB integration in Blender and Cycles

As requested by a handfull, here's some code :)

(NOTE:) you'll need to disable compilation with OSL and install OpenVDB separately.

Reviewers: dingto, lukastoenne, sergey

Subscribers: levon, #cycles

Differential Revision: https://developer.blender.org/D1308

Export: take adaptive domain into account (still a bit off but seems to
work)

Support compilation with SCons (only tested on Linux).

Modification to the node's UI:

- avoid drawing properties' names
- give it a default size
- warn about OpenVDB not being available on the GPU

Correction to some CMakeLists.txt (missed those in some previous commit)

Improvements to compilation with CMake: set flags to be able to build
with or without OpenVDB.

Scons support should follow.

Add OpenVDB version to the system info file

Properly set the fluid transformation matrix.

This time for real, though we need to account for adaptive domain, but
that's for another commit I guess.
Also add metadata to the grid to mark it as in local space.

Make OpenVDB cache properties its own struct/linked list, including some
operators to add caches to, move caches around and remove caches from
the list.

Quiet warning.

Cleanup: unessecary use of Object in get_fluid_description, also make it
static.