Implement tearing control protocol

[nixigaj]

For those that want to create Wayland native games using winit with the option to disable V-sync, my guess is that the tearing protocol would need to be implemented here first. There isn't really a lot of documentation about it right now though.

[kchibisov]

I'm 99% sure it should be done in mesa/video driver directly. It could also be done in softbuffer directly if you want it for shm drawing.

So implementing it here is not really required.