Clone location - Refactor

Introduces cloner classes into lib/cloner and exposes Cloner::LocationCloner via a rake task...

```
rake clone:location[source_location_id,target_location_id]
```

Also exposes a "hidden" UI at "/location_cloner"...
![image](https://cloud.githubusercontent.com/assets/486358/4813869/31adff9c-5ecc-11e4-9d67-edbb444d65f3.png)

https://www.pivotaltracker.com/story/show/81225362