Comment 4 for bug 772754

This is a variation of the mockup from the previous comment. The main point of it is to show that the "Other subscribers" might go to an overlay.

Notes:

 * "View other subscribers" displays if there are other subscribers. Otherwise, the text is "No other subscribers" or similar. We do not try to count or approximate subscribers other than this non-zero/zero distinction.
 * Other notes from previous comment still hold.

Advantages:

 * When a bug has a lot of subscribers, the page does not scroll down as far (though if we really cared about this, we could do a CSS overflow:scroll in a portlet box just as well as the overlay).
 * We don't have to load the "other subscribers" information (which can be a lot of database work) unless the user actually wants it.

Challenges:

 * A number of the actions in the overlay might normally imply another overlay--in particular changing the subscription level of a team. An overlay on an overlay is unacceptable. We would have to carefully design the UI for this change. The portlet approach does not have this challenge.

Disadvantages:

 * Users have to make another action in order to see the subscribers. I have a guess that this has already been rejected in the past when we were trying to optimize the page, but maybe not.
 * "Subscribe someone else" goes more naturally in the list of subscribed users, rather than floating off next to the "view" link, IMO. If you put it in the list of subscribed users as an overlay, you may be back to the overlay-of-an-overlay challenge.

My opinion is that the portlet solution from the previous comment has fewer problems at this stage. I will choose it unless someone is a champion for this overlay approach who provides compelling responses to the challenges and disadvantages...or unless someone higher up rejects them both. :-)