Blender Git Loki

Removed ListBase code for multiple point caches from blenkernel and RNA.

Removed the ptcache ListBase linking in readfile. Only the single
point_cache pointers are used now, which conveniently are already the
active point caches, so we can just ignore the lists (setting them to
the same pointer though to avoid potential problems with forward
compatibility).

Point cache index 1 in smoke domain is not used.

Revert "Comment on smoke caches is deprecated."
Thought this was referring to the ptcaches ListBase, but actually means
the point_cache array, so i still important.

This reverts commit 8f48294bd00b61bae93f375dc0a730cac7fb594e.

Set the G.is_rendering flag and lock editor drawing during export.
This is a terribly hack which is necessary to prevent draw methods
accessing the same data that is written by the export job.

Take the global G.is_break flag into account for stopping the point
cache export job.

Disabled UNDO for the export operator, it doesn't make sense anyway.
Cache files are external outside the undo system and can not simply be
restored.

Correct time sampling for Blender frames: The cycle time is 1.0 by
default, this needs to be 1/fps. The default frame sampling can be added
by writers, Alembic will only create this sampling once internally.

Made all point cache DNA members relating to cache lists DNA_DEPRECATED.
This includes the ListBase ptcaches members in all the users as well as
the next/prev pointers in the PointCache struct.

Moved the new point cache settings DNA data into the existing PointCache
struct. Adding new DNA data alongside the existing structs leads to
a lot of name conflicts, better try to stay within existing structs and
gradually extend/replace struct members.

Comment on smoke caches is deprecated.

Keep a reference to the stop, do_update and progress variables from
the export job in the exporter class, so the exporter can communicate
back to the main thread. This could be done nicer, but is ok for now.

Incomplete dummy function for baking.

Added a new DNA file DNA_pointcache_types.h for all point cache related
structs and enum values. DNA_object_force.h was use previously, this is
a badly named file with a hodgepodge of different areas.

New settings struct for poin caches (unused still).

Make sure the output directory for cache files exists before trying
to create the Alembic OArchive, otherwise HDF5 throws an exception.

Removed the writer_create/reader_create callbacks in PTCacheID, will focus on baking first and see about overhauling the API later.

Added new operator for point cache 'Export'. This is basically the same as baking, naming may have to be adjusted later, for now they just exist side-by-side.

Added boost includes and a thread utility file for mutex and locking.

Exporter class to handle baking of point cache data over a frame range. This uses a mutex and cancel flag to make it work in the job system.