(nnimap-process-expiry-targets): New function.
(nnimap-request-move-article): Request the article before looking at
what the Message-ID is. Fix found by Andrew Cohen.
+ (nnimap-mark-and-expunge-incoming): Wait for the last sequence.
* nnmail.el (nnmail-expired-article-p): Allow returning the cutoff time
for oldness in addition to being a predicate.