Only return people you are not following

This change removes people that you already follow from the list.

When I logged into the site, I was expecting to see people who were following me but I wasn't following.  Instead, it showed only a handful of people I was already following.  If I pressed "Follow all friends back" who would I be following?

With this change, it only shows the people that I'd follow if I pressed the button.

![octostalker - be nice and follow back who follows you](https://f.cloud.github.com/assets/148768/1726806/5fba4492-6295-11e3-9507-efcbd3417fd2.jpg)