since enough bmesh operations can also take advantage of direct index lookups on verts/edges/faces.
developers note:
- EDBM_index_arrays_init/ensure/free -> BM_mesh_elem_table_ensure/init/free
- EDBM_vert/edge/face_at_index -> BM_vert/edge/face_at_index
- EDBM_uv_element_map_create/free -> BM_uv_element_map_create/free
- ED_uv_element_get -> BM_uv_element_get
internal improvement to editmesh_bvh.c
- optionally pass cage-coords as an arg, rather then calculating the coords in BKE_bmbvh_new(),
since all callers already have coords calculated.
- de-duplicate coords creation function from knife and bmbvhm, move into own generic function: BKE_editmesh_vertexCos_get()