[Pidgin] #4509: Support XMPP Invisibility

[Pidgin]

#4509: Support XMPP Invisibility
--------------------+-------------------------------------------------------
 Reporter:  js      |        Owner:  deryni
     Type:  defect  |       Status:  new   
Milestone:          |    Component:  XMPP  
  Version:  2.3.1   |   Resolution:        
 Keywords:          |  
--------------------+-------------------------------------------------------

Comment(by js):

 For invisible to work, we could just create a list, call it invisible and
 activate it. That are two stanzas.

 For privacy lists, we can have predefined lists like blocked, visible,
 etc. These are 2 stanzas. They could be created on connecting and deleted
 after that.

 No, Pidgin does not need to know which client to answer and which not, as
 privacy lists are server based. If you block outgoing presence, outgoing
 presence is blocked. If you block incoming messages, you won't have any
 message you can answer to to leak presence.

-- 
Ticket URL: <http://developer.pidgin.im/ticket/4509#comment:14>
Pidgin <http://pidgin.im>
Pidgin