Interface for granting/revoking badges from admin user page

Main issues with this right now are:

* Grant button alignment
* Validation errors result in a generic error message similar to the badges page, will fix both of these later.
* Should not display badges that have already been granted in the grant badges dropdown.

Will fix those later, this can be merged in the meantime.

This is what it looks like right now:

![screen shot 2014-03-19 at 8 02 26 pm](https://f.cloud.github.com/assets/31063/2461098/62b74340-af73-11e3-833f-24fd9e6c42b3.png)