When changing hostname, also update ejabberd and jwchat.
Restart avahi-daemon after changing hostname to update mdns.
Rearrange xmpp hostname change scripts so we can only restart ejabberd once.
When changing XMPP hostname, make sure user accounts get copied to new database. We are back to 2 ejabberd restarts though.
Don't need 2nd restart.
Merge pull request #66 from jvalleroy/xmpp-hostname

Update XMPP and mDNS when changing hostname