modulemanager: try distinguishing between unloads and reloads. (Fixes #53)
mod_dialback: shut s2s strict mode warnings on module reloads.
mod_s2s: save response attributes on the session stream for outgoing ones.
mod_dialback: check for the legacy dialback stream attribute for RFC 3920 backward compatibility.
mod_dialback: fix typo in the code and update versioning.