Holds the current orientation of the device if the device has an accelerometer. An instance of Accelerometer is available as {@link Splat.Game#accelerometer}.
@constructor
function Accelerometer() {
  /**
   * The angle of the device rotated around the z-axis. The z-axis is the axis coming out of the device screen. alpha represents how much the devies is spun around the center of the screen.
   * @member {number}
   */
  this.alpha = 0;
  /**
   * The angle of the device rotated around the x-axis. The x-axis is horizontal across the device screen. beta represents how much the device is tilted forward or backward.
   * @member {number}
   */
  this.beta = 0;
  /**
   * The angle of the device rotated around the y-axis. The y-axis is vertical across the device screen. gamma represents how much the device is turned left or right.
   * @member {number}
   */
  this.gamma = 0;

  var self = this;
  window.addEventListener("deviceorientation", function(event) {
    self.alpha = event.alpha;
    self.beta = event.beta;
    self.gamma = event.gamma;
  }, false);
}