Circular references between hands/pointables/gestures

```coffeescript
work: (my) ->
  my.leapmotion.on 'hand', (hand) ->
    Logger.info hand.pointables
    #=> [ [Cylon::leap::Pointable] ... ]

    Logger.info hand.gesture
    #=> [Cylon::Leap::Gesture - swipe]
```

:shaved_ice: