Phaser.CANVAS_CLEAR_RECT is a boolean. If 'true' (the default) it will context.clearRect() every frame. If false this is skipped (useful if you know you don't need it)
Collision now works between Sprites positioned via sprite.x/y, sprite.body.x/y or sprite.body.velocity.
If you are tweening a sprite and still want physics collision, set `sprite.body.moves = false` otherwise it will fight against the tween motion.