BitmapData.alphaMask can now also take a Phaser.Sprite, Phaser.Image or BitmapData object as a source type.
BitmapData.alphaMask has 4 new optional parameters: x, y, x2 and y2 to control exactly where the source and mask images are drawn.
BitmapData.alphaMask 'mask' parameter is now optional, if not given it will use itself as the mask.
BitmapData.alphaMask now calls BitmapData.update after running.