Automatic Transition Registeries

These two files register all of the easing curves and physics transitions to TweenTransition and Transitionable respectively. This enables developers to define transition definitions in straight JSON, and not have direct references to Easing functions. 

```js
// once in the application
require('famous/transitions/RegisterEasing');
require('famous/transitions/RegisterPhysics');

// Tween Transition 
myModifier.setTransform(Transform.identity, { 
  curve: 'outExpo',
  duration: 500 
})

// Physics
myModifier.setTransform(Transform.identity, { 
  method: 'spring',
  period: 500,
  dampingRatio: 0.25
})
```

It's a lot easier to use, instead of requiring in Easing every time a transition is desired. 
```js
var Easing = require('famous/transitions/Easing');
myModifier.setTransform(Transform.identity, { 
  curve: Easing.outExpo,
  duration: 500 
})
```

@michaelobriena