This patch extends the mirror modifier a bit. It adds an option for bisecting along the mirrorplane, and provides a shortcut to mirror across the world origin. This makes the mirror modifier quite a bit more flexible in various scenarios.
Quick Demo Video:
Im quite new to the C side of things, so bear with me if things are done wrongly.
This patch just hooks up the existing bisect implementation before the mirror operation.
bmesh_bisect_plane.c seems the be built for operater use, and I'm not sure if just shutting these calls off with bm->use_toolflags is the right way to go about - but for ex. bmesh_bevel.c is apparently doing it this way too...
The modifier UI has been a bit restructured because of the added options, I also tried to regroup the uv options in a more sane manner.
Thanks for your time, I know you guys are busy..