Smack's previous entity caps implementation assumed that an entity lost
its entity caps feature as soon as a presence without caps from that
entity was received. But according to XEP-0115 § 8.4, this is a
perfectly normal optimization technique. We now reset the caps state
after an available presence becomes unavailable.
Also introduce PresenceEventListener, which is required for this
feature.
Also make Roster.preApprove() take a BareJid as argument.
Fixes SMACK-723.
Make Roster entries Map from BareJid to RosterEntry, since only
bare JIDs are allowed as roster items as per RFC 6121 § 3.1.1
When a user sends a presence subscription request to a potential
instant messaging and presence contact, the value of the 'to'
attribute MUST be a bare JID <contact@domainpart> rather than a full
JID <contact@domainpart/resourcepart>,…
Also some further Roster API changes regarding JIDs.
Florian Schmaus
Tomáš Havlas