v0.23.0 — sculpt scissors

New tool: physics_sculpt_cut — cut a hole through a Mesh sculpt, or a piece off it. A polygon in the body's frame is swept straight through along a direction and taken out (or kept, with mode 'keep'); the cut is filled with new faces unless cap is false. A cut that splits the clay makes one body per piece and reports them in bodies. 229 tools.

Also includes 0.22.1 (etch_combine's join and unjoin ops), which was tagged but never released.