Now CD_SHAPEKEY_INDEX customdata is stored in edit-mode when hooks and vertex parents are used.
This also fixes a bug where undo would loose key-index data.
Move to structs for BM_mesh_bm_to/from_me to avoid passing many argument, which mostly aren't used.
add arguments to calculate normals when converting to bmesh:
BM_mesh_bm_from_me, DM_to_bmesh
This gives some speedup to undo (which didnt need to re-calculate vertex normals), and array modifier which doesnt need to calculate face normals at all
- moved mesh conversion functions into their own file.
bmesh py api:
- can now create a new empty bmesh without first creating mesh data.
- added function to copy bmesh data back to a mesh.
- bmesh.from_mesh() can now get a mesh which isnt in editmode.
