Remove references to GameMath, it's just Math now

Throw exceptions if wrong format given to tilemap or textureatlas. Previously, old onload remained active and error happened in the wrong (and hard to diagnose) place.

src/core/State.js

@@ -50,7 +50,7 @@ Phaser.State = function () {
     this.load = null;
     
     /**
-	* @property {Phaser.GameMath} math - Reference to the math helper.
+	* @property {Phaser.Math} math - Reference to the math helper.
 	* @default
 	*/
     this.math = null;