[Spambayes] IMAPFilter trainingissues

[Meyer, Tony]

> Looking at it again, it appears that it's the $ in  "3 (FLAGS (\Seen 
> $MDNSent) UID 3)" which is causing the problems.
> I've changed the regular expressions in _extract_fetch_data 
> to allow $ symbols in flags, which means the UIDs get picked up now.

I wasn't aware that the $ character was valid in flag names (I ought to
have checked...it's about the point where I need to have the imap RFC
printed out and stuck to my wall ;).  Turns out that anything apart from
(,),{, ,ASCII chars 0x00 - 0x1f, 0x7f,*,%,\," is valid.  I'll update the
regex to reflect this.

> Where there are multiple flags, the regex still only picks up the
first 
> one, which could be a problem if a message is marked "\Seen"
"\Deleted"
> - the filter would pick up the deleted message.

This is a different problem - I'll fix this too.

=Tony Meyer