Highlight org.clojars.* forks [issue #77]

This highlights org.clojars.* forks with italics anywhere jar-link is used, 
which includes:

* the search results page
* the dashboard
* the projects browse page
* the header on the jar view page
* the header on the versions page (another change in this commit)
* probably other places I'm not aware of

It also adds a notice to the view page for a jar if it is a fork, and a
notice to the top of the search results if any forks are in the result set.
The notice links to the Groups wiki page for more information.