[Dave Cridland] try to encode username, realm and password in iso-8859-1 when doing DIGEST-MD5 before computing the hash. Fixes #5512

update README file to depend on python-dbus >=0.81, which is needed for bus.list_names() function. Fixes #5474

don't show in roster / notification that a contact unsubscribed us if we already popup up the dialog. Fixes #5470

Approach: Keep filling the receive buffer until we have found enough data to extract the first HTTP header and body