Blender Git Loki

Sculpt: BMLog stuff

* BMLog now has a more fine-grained logging
facility to track the call chains
that produce specific log elements.
* Wrote a new function in bmesh_core.c to
dump local geometry around an element to
stdout in .obj format.
* Edge collapse now properly handles the
fact that bmesh handles sharp flags
inversely, i.e. edges *not* marked
with BM_ELEM_SMOOTH are sharp.

* Wrote a new BMLog API that handles elements
undergoing topological changes a bit better.
- BM_log_[edge/face]_[pre/post]
- Idea is to call the _pre before calling
collapse or split edge, then _post afterwards.
- No longer need to assign new IDs
in certain cases to avoid confusing BMLog.
- Other parts of BMLog may now be redundant;
need to check.

* Deleted some #if 0'd code
* Fixed a bug in BLI_smallhash_ensure_p, it didn't properly
set up state for when smallhash is used as a very simple
set.