Marking a bug as duplicate should change the status to Duplicate, so that the status shows up a listing of bugs.
This also affects the Latests bugs portlet.
The implementation plan looks like this:
* Add IBugTask.display_status, which returns the appropriate
* Change all the template code, that uses task/status/title,
to use task/display_status.
* We don't want people editing duplicate bugtasks, so changing
EditBugTask.checkAuthenticated() to return False if the bug
is a duplicate is probably a good idea. Maybe even redirect
+editstatus to +viewstatus, with an appropriate notification
I think that's all that needs to be done. Changing all the call sites is probably the most tricky one, since there are quite a few, the bug page, all the buglistings, portlets, and so on. A test should be added for every call site that is changed.