Gamepad.js API plugin

EXAMPLE:

Put the following in your main.js update loop:

var gamepad = new Gamepad.getState(0);      
    var mappings = [[ gamepad.dpadUp, ig.KEY.UP_ARROW ],
                    [ gamepad.dpadDown, ig.KEY.DOWN_ARROW ],
                    [ gamepad.dpadLeft, ig.KEY.LEFT_ARROW ],
                    [ gamepad.dpadRight, ig.KEY.RIGHT_ARROW ],
                    [ gamepad.faceButton0, ig.KEY.X ],
                    [ gamepad.faceButton1, ig.KEY.C ],
                    [ gamepad.faceButton2, ig.KEY.Z ],
                    [ gamepad.faceButton3, ig.KEY.V ]];
    new Gamepad.magic(gamepad, mappings);