WebGL context loss messages

[1j01]

I made it reinitialize the WebGL context everytime it resets the state, to make things much simpler.
But I apparently should clean up the WebGL context (explicitly) before discarding it.
(Or maybe go back to trying to reset everything without destroying the context.)

https://stackoverflow.com/questions/37072303/how-to-free-and-garbage-collect-a-webgl-context
https://stackoverflow.com/questions/23598471/how-do-i-clean-up-and-unload-a-webgl-canvas-context-from-gpu-after-use