ubx: conform to NMEA termination with CR-LF
ubx autobaud: wait for entire autobaud message to be transmitted

The baud rate on the link was being changed part-way through the
transmission of the NMEA message which would result in a failure
to change away from lower baud rates (<= 9600baud) due to the
low-rate message being corrupted on the wire.
Merge pull request #1067 from solidgoldbomb/autobaud-delay-fix

Autobaud delay fix