make ArchiveIterator use a single format for the message list instead of having to switch back and forth.  this also preps for future changes to do things like sending the whole message to clients, etc.
make ArchiveIterator use a single format for the message list instead of having to switch back and forth.  this also preps for future changes to do things like sending the whole message to clients, etc.

git-svn-id: e9fe9b84e32fc5e57b7d09c40cd78b14ea28ed71@406006 13f79535-47bb-0310-9956-ffa450edef68

apache/spamassassin,apache/spamassassin,apache/spamassassin,apache/spamassassin,apache/spamassassin