Issue navigation bar

This patch set removes issue related navigation links (not review related!) from the body and adds a new navigation bar at the top.

I think it improves usability and gives a more consistent look to have all these navigation links present when viewing issue related pages. At the moment there are some pages, e.g. edit issue, where's no link back to the issue.

[GvR, 2008-05-19 02:06:48]

Not bad, but I think you can go even further.

The "Start review" link should also go in this toolbar, and I think that the
brief issue description should also go there, leaving only the Description in
the main Issue page.

[GvR, 2008-05-23 19:07:36]

[removing an alias]

[GvR, 2008-05-27 22:42:46]

I'm still trying to like this, but I think it needs some more refinement.  E.g.
it's ugly to see the issue title show up twice when viewing the issue or edit
page, and likewise to see the edit link appear on the edit page or the publish
link on the publish page.

I wonder if what we really need is some kind of navigation side bar, instead of
the menu at the top...