Community Partners on the map

This pull request implements showing community partners on the main map. Currently, all community partners are shown at all times. Community partners are differentiated from regular trips on the map by having white markers.

Gmaps for rails apparently assumes that you're never going to have two different kinds of markers on the same map, so I had to do a bunch of semi hacky stuff to get around that (most prominently the stupid JSON loading and dumping in `map_controller.rb`). We can look into fixing it later.

I apparently don't have access to calblueprint/altbreaks and it is almost 5 in the morning, so I forked it and I'm submitting this request from my fork.

Here's a picture:

![screen shot 2013-09-05 at 4 47 20 am](https://f.cloud.github.com/assets/1168853/1087819/56df4c38-1622-11e3-8952-f22995f15e53.png)

I'm going to need a lot of [coffee](http://25.media.tumblr.com/53153295f55460720a70bf3eb6af3e75/tumblr_msfh710AV31s30ko5o1_500.gif) tomorrow.