Keyboard.justPressed has bee renamed to Keyboard.downDuration which is a much clearer name for what the method actually does.
Keyboard.justReleased has bee renamed to Keyboard.upDuration which is a much clearer name for what the method actually does.
Keyboard.downDuration, Keyboard.upDuration and Keyboard.isDown now all return `null` if the Key wasn't found in the local keys array.