This PR addresses some issues with webgl contexts - Fixed issue when WebGL context lost occurs where there was no friendly output to the user - Fixed issue where HiDPI scaling could accidentally scale past the 4k mobile limit, if the context would scale too large it will now attempt to recover by backing off. - Added way to add custom WebGL context lost/recovered handlers for your game ```typescript const game = new ex.Engine({ handleContextLost: (e) => {...}, handleContextRestored: (e) => {...} }) ``` Default context lost screen