Blender Git Loki

Printf-style method of calling operations now take a modified format string,
like so:

[opname] [slotname]=%[format code]

Before it was relying on the input format codes being in the same proper
order as the slots, which seemed like a potential maintainance nightmare to
me. Also the flags for creating buffers from bmop flags or header flags,
now support additional modifiers for combining vert/edge/face inputs.
E.g. %hfvef would accept all geometry with a header flag, and
%fef would accept edges and faces with a certain bmop flag set.

Example from the UI code:

if (!EDBM_CallOpf(em, op, "del geom=%hf context=%d", BM_SELECT, DEL_ONLYFACES))
return OPERATOR_CANCELLED;

(remember EDBM_CallOpf is the UI wrapper for this that does conversion,
error reporting, etc).

On todo is cleaning up/splitting bmesh_operators.h,
since it's kindof a mesh right now. I'm thinking of adding the slot
names in comments next to the slot ids, but I definitely would have to
clean up bmesh_operators.h first, or it'd just be too chaotic for me.
BTW, the operator API should now have enough meta info to wrap with
a scripting language, not that it matters since that's not happening till
much much later.

Also hopefully corrected some SConscripts, fix mostly provided by Elia Sarti,
though I also copied some SConscripts from 2.5 (not sure if doing
so was especially helpful).

Finally, I refactored a few places to use the new operator calling api,
as an example of how this is beneficial.