Merge pull request phaserjs#1536 from belohlavek/master

Fixed wheelDelta type on Typescript definition file

Author: photonstorm

typescript/phaser.d.ts

@@ -2137,7 +2137,7 @@ declare module Phaser {
         _wheelEvent: WheelEventProxy;
         pointerLock: Phaser.Signal;
         stopOnGameOut: boolean;
-        wheelDelta: WheelEventProxy;
+        wheelDelta: number;
 
         onMouseDown(event: MouseEvent): void;
         onMouseMove(event: MouseEvent): void;