The result of a SEND message is now an option.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Make most of the switch into a library, so it can be tested via the toplevel.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Regenerate OASIS.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>