added gamepad support and some samples

Hi @cykod :)

I wrote a little plugin for quintus to support gamepads :)
I use the fantastic lib https://github.com/inequation/gamepad.js and wrote some code arround it so it maps the events from gamepad.js to quintus.

The only things todo, to use this is to include the gamepad.js and the quintus_gamepad.js

In the game code only something like this must be called when initializing Quintus

var Q = window.Q = Quintus()
        .include("Sprites, Scenes, Input,GamePadInput, 2D, Anim, Touch, UI")

I added in the examples folder two new examples which are showing that it works ;)
platformer_tmx_gamepad 
tower_man_gamepad

At the moment only Xbox360 gamepads are configured.