Martin - Added mouse click button - Removed spaces - Formatted some lines

Basically I added mouse support for the aimer. Most of the lines are just formatting except these two:
menu.js
    game.input.onDown.addOnce(this.start, this);
play.js
    game.input.onDown.add(this.movePlayer, this);
This is capturing every signal (both touch and mouse events) that happens on the game. We will have issues later if we want to place buttons on the GUI in-game (becouse the events will be captured by this instead).
If you want specific Mouse interaction, I would recommend using 
http://docs.phaser.io/Phaser.Mouse.html