Rock Paper Scissors CA script

Runs a rock paper scissors cellular automata voxel wall. Up to 9 (changeable in script) instances of this script can be run simultaneously and they will each control a portion of the wall. This may be run on ACs, but the number of voxel changes is very high, so it's not quite feasible for a large wall yet.

NOTE: You have to run each script one at a time, right now there is a race condition since scripts cannot yet mutex lock voxel resources, and they do not have atomic operations. Some work needs to be done to overcome this.

Also fixes a few small bugs related to the scripting interface.
Since we only have one instance of the scripting engine, I think it would be cleaner to make this mutex a member variable of the scripting interface object. It's the same effect, but is more consistent with the other member variables like the _undoStack.