Add validations to forms

Added validations to all inputs and display them in tooltips

![rejection-reasons-validations](https://cloud.githubusercontent.com/assets/2394509/3808817/5b336452-1c7c-11e4-95d8-5674657bfb2f.gif)

Backbone collections are extends with some of the the underscore methods, so you can simply
```coffeescript
App.Collections.rejectionReasons.reject(...)
```