* Game has a new property `hasFocus` which is a read-only boolean that lets you know if the window the game is embedded in (including in an iframe) currently has focus or not.
* Game.Config has a new property `autoFocus`, which is `true` by default, and will automatically call `window.focus()` when the game starts.
* Clicking on the canvas will automatically call `window.focus`. This means in games that use keyboard controls if you tab or click away from the game, then click back on it again, the keys will carry on working (where-as before they would remain unfocused)
