Can't search issues where assignee is 'nobody' (BB-662)

Hi all,
if I have to specify two criteria for the same parameter, query will use only the last one. That's because there is collision of GET variables (&

=value) with the same name, the last overwriting the others.

As you are working on queries, I might find it useful to filter out tickets which are not assigned (responsible=nobody), but as "nobody" is not mapped in the database (I think so), this does not work yet.