Phaser 2.4.3+ support

[Owumaro]

Starting with Phaser 2.4.3, the Phaser.Canvas.create method has changed :
create(width, height, id) => create(parent, width, height, id, skipPool)

Therefore this plugins doesn't work anymore because of this line :
this.scaledCanvas = Phaser.Canvas.create(this.scaledWidth, this.scaledHeight);

The width value is interpreted as parent argument and the height goes in the width. height gets the default value.
To solve this, I replaced this line with :
this.scaledCanvas = Phaser.Canvas.create(null, this.scaledWidth, this.scaledHeight, null, true);

[beeglebug]

Looks good! Please open a pull request with your change and I will get it merged in.