Set the priority string to a concatenation of the connection cipher and curve strings, falling back to the context ones if the connection value isn't specified. Also get context.c to specify NULL for default context list and the opportunistic list for the connection, moving these library-specific quantities into the specific implementation.
Add a flag to the context (so, it's actually got something useful there!) and check the connection version on a successful handshake.
This means we need to access the context from a connection, so add a pointer to the context to the connection.
Jim Hague