clear unused classes
persist Subscription request to a standalone field in target account, so
that a account can more easily get unread subscription when login
now a user read unread subscription request from a standalone field
deal with subscribed presence
deal with presence subscribed
append contact state in the response of roaster request
encode 'ask' attribute of contact
normalize received <presence />
unify to use XmppContext.flush() to write message
log inbound/outbound message at XmppContext instead of Netty handler