Typeahead roles

Adds roles to the typeahead dropdown.

Looks like this:

![screen shot 2014-10-01 at 9 59 20 am](https://cloud.githubusercontent.com/assets/1903518/4476139/2bb04f8c-4973-11e4-944b-da5a988d916c.png)

- shows collaborators on top, but shows duplicates. We are planning on fixing that issue with the migration to select2

Example:

![screen shot 2014-10-01 at 10 00 20 am](https://cloud.githubusercontent.com/assets/1903518/4476153/4e1a06ee-4973-11e4-8005-19f02ee8e799.png)



I believe we usually do, but for the sake of simplicity we ensured anything using typeahead just passed it an array. We probably could have just consumed the root key on the parent of the typeahead component though.