Docs update.

Author: photonstorm

README.md

@@ -358,6 +358,7 @@ You can read all about the philosophy behind Lazer [here](http://phaser.io/news/
 * InputHandler.checkPointerDown had an incorrect single pipe character |, instead of an OR check ||, and an `isDown` check, causing Button Over events to fail (thanks @pengchuan #2486)
 * BitmapText objects with lines greater than `maxWidth` now handle alignment values correctly, causing them to properly center align (thanks @kevinleedrum  #2499 @crippledcactus #2496)
 * Text has a new private method `measureLine` which is used to calculate the final Text line length, after factoring in color stops and other style changes. This should prevent characters from becoming truncated (thanks @TadejZupancic #2519 #2512)
+* Sometimes the browser would cause a race condition where any connected Game Pads were being detected before the callback had a chance to be established. Also sometimes the rawPad references would become stale, and are now checked constantly (thanks @cwleonard #2471)
 
 ### Pixi Updates