[Bf-codereview] Convex hull bmesh operator (issue 6114060)

[NicholasBishop at gmail.com]

Reviewers: bf-codereview_blender.org,

Description:
As part of my skin modifier work I added a convex hull operation. I
think this can be useful as a general modeling tool, this patch contains
the BMesh operator and corresponding MESH_OT_convex_hull.

Example:
http://nicholasbishop.net/wordpress/wp-content/uploads/2012/04/hull.gif



Please review this at http://codereview.appspot.com/6114060/

Affected files:
   source/blender/blenlib/BLI_ghash.h
   source/blender/bmesh/CMakeLists.txt
   source/blender/bmesh/intern/bmesh_opdefines.c
   source/blender/bmesh/intern/bmesh_operators_private.h
   source/blender/bmesh/operators/bmo_hull.c
   source/blender/editors/mesh/editmesh_tools.c
   source/blender/editors/mesh/mesh_intern.h
   source/blender/editors/mesh/mesh_ops.c