Blender Git Loki

Made group work from multiple selection's (before it used the first selected face/vert/edge)
so you can select 2 faces and then get all coplaner faces around both.
Added fp to face and edge edit data so as to store edge length and face area/perimeter. (in the union so minimal overhead)
current implimentation is fairly optimized.

Change to arithb.c was just to command Inpf as being the dot producr.