interface workings

For Beta-3 our API should be much cleaner than it currently is, both on the public interface and internally. This means some "spring cleaning".

#931 - implement soy._internals.LoopThread?

#910 - move soy.Window to,, and

#930 - move _coreLoop physics processing code to a cdef function of soy.scenes.Scene

#932 - move Transport _coreLoop handling to it's own module, cleanup reference to it, etc

Documentation should take place during this move.

Tagged API