Add metro search after selecting institution

High level:
* Adds a page after selecting institution which has an auto-complete for metro
* After selecting metro, jump to the map, centered on selected metro

Specific comments:
* metro_search.html: add cfpbstyles
* map.js, index.html, views.py: If passed a metro, look it up and pass the associated object to the template. The template then displays the lat/lon of its centroid as data attributes, which are read at init time for the map
Use the data attributes (which indicate centroid) if available, defaulting to Chicago
* models.py/views.py: Moved a function (`formatted_name`) from a serializer into this model. Also, renamed a function (hence multiple changes to `url` and `reverse` calls
* metro_search.js: Ajax completion for metro name. Only allow the "select" button to be used when a metro is chosen -- deactivate when altered. A user can still press enter to submit, they just won't have a metro.

Template matches @micheletepper's wireframe:
![screen shot 2014-07-29 at 11 23 40 pm](https://cloud.githubusercontent.com/assets/326918/3744775/1920a436-1799-11e4-80cb-c385c26001b4.png)
![screen shot 2014-07-29 at 11 24 01 pm](https://cloud.githubusercontent.com/assets/326918/3744777/1fbd1086-1799-11e4-8d5a-f4393da70d05.png)