Structure of a session:

session {

	-- properties --

	conn -- the tcp connection

	notopen -- true if stream has not been initiated, removed after receiving <stream:steam>

	type -- the connection type. Valid values include:

			-- "c2s_unauthed" - connection has not been authenticated yet

			-- "c2s" - from a local client to the server

	username -- the node part of the client's jid (not defined before auth)

	host -- the host part of the client's jid (not defined before stream initiation)

	resource -- the resource part of the client's full jid (not defined before resource binding)

	full_jid -- convenience for the above 3 as string in username@host/resource form (not defined before resource binding)

	priority -- the resource priority, default: 0

	presence -- the last non-directed presence with no type attribute. initially nil. reset to nil on unavailable presence.

	interested -- true if the resource requested the roster. Interested resources receive roster updates. Initially nil.

	roster -- the user's roster. Loaded as soon as the resource is bound (session becomes a connected resource).

	-- methods --

	send(x) -- converts x to a string, and writes it to the connection

	close(x) -- Disconnect the user and clean up the session, best call sessionmanager.destroy_session() instead of this in most cases

}

if session.full_jid (also session.roster and session.resource) then this is a "connected resource"

if session.presence then this is an "available resource" (all available resources are connected resources)

if session.interested then this is an "interested resource" (all interested resources are connected resources)