v0.16.0 parallel

This release adds full parallel processing capability. You don't need to do anything to benefit; LiSE will evaluate all your rules' trigger functions in parallel by default. If you like, though, the engine has a new pool attribute that is an Executor implementation, capable of distributing work among however many cores your processor has. Submit code you've stored in function.py or method.py to it.

ELiDE reacts to graphics changes in the LiSE core once again.