delayed message handling and Priority option
Nickname can be specified when joining MUC

Client.JoinMUC now accept second argument as nickname.
Merge pull request #42 from seletskiy/master

Nickname can be specified when joining MUC
export XMLescape
add sending of raw string/[]byte stanzas
Merge branch 'master' of https://github.com/mattn/go-xmpp
merge join muc change

Conflicts:
	xmpp_muc.go