qtest: add in-process incoming command handler

The handler allows a qtest client to send commands to the server by
directly calling a function, rather than using a file/CharBackend

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Message-id: 20200220041118.23264-9-alxndr@bu.edu
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2 files changed