Blender Git Loki

EditMode armature: mirrored editing feature.

- Option is in EditButtons, Armature panel.
- Currently only local X-axis mirror (seems to be default anyway)
- Transform then applies changes to the mirrored-name bone as well.
- Extrude: also does the counterpart Bone
- New: SHIFT+E extrude: extrudes 2 mirrored Bones out of a normal Bone.
(creating names by appening _L and _R)

Or in short: you can now model a full rig without any manual naming!
Of course the names are not too nice... a couple of ideas to explore;
- rename a mirrored bone renames counterpart too
- allow in weightpaint mode to select Bones
- and of course mirrored edit in PoseMode (if that's useful...)

Important note: I tweaked the naming convention a bit; names like
Bone_L.005 and Bone_R.005 are considered counterparts. However, if
you use the "Flip names" option, the number extension is still
truncated.

BTW: Commits in Zr's code are fixes for gcc warnings. :)