TODO
====

 - Implement local LIST/TYPE command
 - Implement DUMP and RDUMP commands
 - Try to reconnect (using dmesg?) to device if we lose connection
   - i.e. when setting OPTIONs
 - Timeout on and retry connections at least once
   - first connection to PicoMite always seems to fail on my {X}Ubuntu VMs
   - does DTR need asserting ? See https://www.thebackshed.com/forum/ViewTopic.php?TID=14155&PID=180669
 - Implement progress reporting for XMODEM SEND and RECEIVE

