Preparing for 2.1.1 development.
Documentation fixes
Merge pull request #1179 from FedeOmoto/dev

Documentation fixes
Unnecessary "if" in Line.fromSprite method
Merge pull request #1180 from FedeOmoto/dev

Unnecessary "if" in Line.fromSprite method
readme update + screen shot
Version 2.1.1. of Phaser is an emergency point release. It addresses a potential race condition that could happen in States that tried to change state from the `create` method but had an empty preloader or pre-cached assets.