Render follow/unfollow button via AJAX.

:fork_and_knife: Currently the follow, unfollow actions redirect back. This causes a bug in Chrome where items in the history stack are duplicated causing the user to have to click back twice. This changes the follow, unfollow button to be a remote link with a ajax:success event bound to it that loads the current view and loads the follow, unfollow button from that into the dom without a page reload. This doesn't really save on page load as it's still rendering the entire view but it does fix the bug and provide a better user experience.