If you're wondering why I used an alert for handling responses but not requests,
it's because the former was easy to do that way but the latter would have
involved some major refactoring or kludging. The DHT node is written with the
(IMO reasonable) assumption that all responses will be generated immediately, so
there was no way to easily accommodate getting a response asynchronously via
an alert.
The session_handle class exposes the same public interface to session_impl as
the session class. The difference being that session_handle does not own the
underlying session_impl so multiple session_handle instances can be created
and copied about as needed.
The intent is to chenge the plugin API to pass an instance of session_handle
instead of a pointer to session_impl. This change will be made in a separate
patch.
To maintain ABI compatibilty, the type signature of session was not changed.
The relevent functions have been modified to forward to session_handle and
all enums have been left in session.