Very tiny library to make a 60 framelimit.
fl60(frameFn) -> undefined
Executed once per program - next executions don't have any effect. Sets frameFn as a callback function that will be executed for each frame - 60 times per second. Starts the loop.
getFPS() -> number
Returns current FPS: a value between 0 and 60. If fl60 was never called returns NaN instead.
fl60 uses setTimeout under the hood.