Blender Git Loki

Added writers for DupliCache data to allow truely successive cache
modification.

The bake operator will now generate output based on the 'source_mode'
setting:
* When the source is SCENE it uses the basic object data as stored in
the Object ID datablocks (DerivedMesh, particle hair strands etc.)
* When the source is CACHE it fills a temporary DupliCache with data
from the cache archive (like it would for the display dupli_cache,
but also supporting render data). This dupli cache is carried over
between frames during baking, which allows modifiers to act as
simulations and sequentially advance motion states.