Provide an option to limit the frame rate of the Stage

[bp74]

Maybe something like

StageXl.stageOptions.maxFrameRate = 30;

[bp74]

Since the html5 "request animation frame" is synced with the display refresh it won't be easy to get an arbitrary frame rate that is still rendered at regular intervals. You only will get constants frame intervals if your frame rate is a fraction of the physical frame rate of the display. For example if the screen refreshes with 60 fps, you should use frame rates like 60, 30, 20, 15, 12, 10, ....