Render/primary loop division

[CaptainN]

Separate renderloop from core loop. Create clock based syncing framework (frameskipping/dynamic framerate).

The idea is to run the main loop on a timer and use advance and sleep functionality to keep the logic synced in time, and run the render loop at a constant 60 (or as close to vsync as we can get) fps.

If this can be done in a multithreaded way at some point we should be able to keep a light render loop moving even when a complex main loop can't sustain a constant frame rate.

Should also be able to support frame rate independent content - 15 and 20 fps swfs running at the correct speed in the same app concurrently.