[Imap-protocol] updated table of IMAP client capabilities

[Mark Crispin]

Pine / Alpine:

Yes:	STARTTLS, SASL (GSSAPI, CRAM-MD5, PLAIN, LOGIN, EXTERNAL),
 	SSL, NAMESPACE, MULTIAPPEND, UIDPLUS, CHILDREN, SORT, THREAD

No:	SASL-IR, ESEARCH, IDLE, LITERAL+, LEMONADE
 	;;; For the purposes of Pine/Alpine:
 	;;;
 	;;; SASL-IR adds complexity just to save one RTT.  We have
 	;;;	enough problems with servers getting SASL right as it is.
 	;;; ESEARCH has no constituency within our user community.
 	;;; IDLE is unnecessary except for mobile devices, and has
 	;;;	problems when NAT is in use.
 	;;; LITERAL+ is not needed since MULTIAPPEND is used instead,
 	;;;	and MULTIAPPEND solves problems that LITERAL+ does not.
 	;;; LEMONADE support is under consideration.

UW imapd implements all of the above except for LEMONADE.  LEMONADE 
support is under consideration.

-- Mark --

http://panda.com/mrc
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.