Also remove the Exceptions from the signature of getRoster().
Extend ConnectionListener with connected() and authenticated()
callbacks, required by Roster to be notified so that the Roster can be
loaded *after* login.
Change all \r\n into unix style newlines. Add missing newlines at the
end of a file and activate the newline checkstyle module, that enforces
'\n' as newline and a newline at the end of every file.