Implement a MSGBUF control packet mechanism based on the command

Implement a MSGBUF control packet mechanism based on the command
request ids.  So far we were only able to have one command in flight
at a time and race conditions could easily lead to unexpected
behaviour.  With this rework we send and enqueue a control packet
command and wait for replies to happen.  Thus we can have multiple
control packets in flight and a reply with the correct id will wake
us up.