Collection fixes

Hey dude, 

I took a look at your code and you made a pretty common mistake w/ the collections. In Meteor, you declare a collection on both the client and server, and then you publish/subscribe on the server only and client only respectively. But you had the collection defined only on the server - which isn't going to work!

I switched to accounts-password because I didn't feel like setting up twitter credentials, feel free to switch back with `meteor remove` and `meteor add` for the appropriate User collections. Also made a few cosmetic changes because I couldn't get anything to display correctly. Most important thing is the one-line file collections/collections.js  - a shared JS file that defines the collection on both client and server!