Process only requested roster results (SMACK-538)

Prior to this change, Smack processes each RosterPacket (which is of
type IQ.Type.RESULT) as a roster result.

Any other client on the XMPP network can send such a packet (not
our server). This allows a malicious party to overwrite our Roster.

This patch changes smack so that a RosterPacket is discarded if it
not a reply to a roster request.
XEP-0198: prevent connectionClosed listener call on connect() failure
Move host/port from ConnectionConfiguration to XMPPConnection

There semantic is that they now report the host used to establish the
connection. Therefore BOSHConfiguration needs to hostAddresses for
getURI().
Move DNS resolving into connect()

It was misplaced in ConnectionConfiguration anyways, as the sole
instantiation of a ConnectionConfiguration should not cause any network
I/O.
Always lookup DNS SRV RR on connect()
MUC: obtain human-readable room name DiscoverInfo
MUC: try to get room name from SDP identity
TLSv1.2 experimental
Added TLS HostnameVerifier