3597 Expand/Collapse Fandoms List broken on own dash

The way we were showing/hiding the Share buttons on a user's own bookmarks was interacting badly with the buttons for expanding or collapsing the list of fandoms on a user's dashboard page. It was also including the JavaScript up to 20 times on a page. Oops.

This changes it so we target the Share button on both works and own bookmarks specifically using #share_button instead of just relying on .actions .hidden.

http://code.google.com/p/otwarchive/issues/detail?id=3597