also added a safety check for the crash, even though reverting fixes.
bmesh_to_mesh_exec() could set me->mface array to NULL but leave me->totface when notellelation=1, which is likely to give trouble elsewhere.
1. Removed pinning, at least until after trunk
reintegration (it's a usefull feature, but
incomplete).
2. Ripped out the subclassing code I originally
wrote so bmesh would be more usable for modifiers
(I ended up improving CDDM instead).
3. Inlined some of the macros in bmesh.h, still need to
do the macros in bmesh_operator_api.h.
4. Removed the BMESH_ITER_*** macros (except for BMESH_ITER_INDEX).
They were too clunkly to be worth it.