GameObjectFactory fixes

game.add.text - Made the text and style parameters optional as these
can be set after creating the text field

game.add.filter - Remover parameters that are no longer required

game.add. plugin - Remover parameters that are no longer required

https://github.com/photonstorm/phaser/blob/master/src/gameobjects/GameOb
jectFactory.js
Merge pull request #33 from adireddy/master

GameObjectFactory fixes