Allow a reduced render rate

[samme]

E.g., if you set game.time.desiredFps to 30, updates are reduced to 30 per second but renders continue at 60 per second, leaving you with 2 renders per update (the second is wasted).

It would be nice if we could skip renders that would exceed the update rate.

[samme]

Example: https://codepen.io/samme/pen/KvNpeN

You can reduce the render rate manually by toggling lockRender on and off: https://codepen.io/samme/pen/wqomNr

[samme]

Update/render plot: https://codepen.io/samme/pen/RZKMMw

[samme]

The FPS calculations would have to be changed. Phaser.Time assumes that every Time#update corresponds to one render (via Phaser.Game#update).

[samme]

I guess this will be Phaser.Game#forceSingleRender. Weird.