Add another active template tag

One template tag is for passing URL regex's, the other accepts the name
of a URL from a URLconf
Fix active collapses

Open the collapse for the link that was just clicked
Fix up sidebar for repos

Keep the "Code" collapse open when viewing the user's repository. Also,
move the help information (clone command, password, help, etc) to a
drop-down on the repo page's nav tabs. That way, the sidebar doesn't
change when viewing the repo's contents.