Draft: Don't give up too early when collecting mime types
requested to merge emmanuel.fleury/xdgmime:Dont_give_up_too_early_when_collecting_mime_types into master
Since returning exactly one match has special significance, don't give up matching before we've found at least 2 types. Also, make sure that we don't return the same mime type more than once. Bug 541236.
Helps: #32