- don't collapse boundary verts into non boundary edges (was ugly causing spikes)
- handle degenerate cases better, rather then removing double edges after collapse, check before collapsing that there won't be any degenerate faces/edges.
- memset(..., -1) is used incorrectly even though it worked: MOD_solidify.c - thanks Halley from IRC for noticing this. use fill_vn_i() instead.
- quiet warnings in editmesh_slide.c
- cleanup comments in bmesh and some other minor comment additions.
- spelling - turns out we had tessellation spelt wrong all over.
- use \directive for doxy (not @directive)
- remove BLI_sparsemap.h - was from bmesh merge IIRC but entire file commented and not used.
* made bmesh_structure.h function names more consistant.
* remove unused code in bmesh_structure.c
* removed 'Edge Flip' operator (missing from bmesh but looked into trunk feature and dont think its worth keeping).
* tagged some BMESH_TODO's
* better type safety for BM_elem_flag_* and BM_elem_index_* functions.
* add BMElem type to be used where BMFace/Edge/Vert/Loop can be interchanged.
* fix bug in select manifold, found when making functions more strict.
* Only have 1 python object per bmesh, vertex, edge, loop, face.
* Store pointers back to the python data in a custom data layer so as not to use more memory for normal editing operations (when pythons not running).
* Currently this data is created and freed along with the BMesh PyObject.
* Incidentally - this fixes comparisons for bmesh elements which wasnt working before.
