[jdev] Presence leak test suite

[Kevin Smith]

> My point is that the server can't just check the suubscription state in the
> roster. Also it introduces a good argument for my proposed best practice of
> sharing presence for ad-hoc chats/interactions:
> http://www.xmpp.org/internet-drafts/draft-saintandre-rfc3921bis-05.html#message-chat

Yes, I've agreed that sharing presence when chatting makes sense for a
while, so I agree with the best practice. It does seem weird to have
that the client MUST allow this to be disabled though - currently,
that section reads that a client is not XMPP compliant (i.e. it breaks
a MUST in the RFC) if it follows the best practices in the RFC :)

/K