Put a shortlog on the repository index page

The repo index page now shows an abbreviated list of branches and tags
along the left-hand side, with the main content area taken up by a
shortlog of HEAD. Since the ref list is now abbreviated, provide a new
/+refs page that shows the unabbreviated ref list. (This unabbreviated
list is still a bit ugly but ends up looking a lot like the old repo
index page.)

Change-Id: Ie72690d5e9b8162f68818782bfdaa568ad319983
12 files changed