v1.3

• Add support for 230 400 bdps.
• Change MTBbus interfae to polling.
• Minor code enhancements.

v1.2

• Fix critical bug with always-setting 'changed' flag.
• Add bootloader; support firmware upgrade directly via USB (DFU).
• Support MTBbus protocol v4.1.

v1.1

• Send at least 1 inquiry between forwarding messages to avoid watchdog
  timeout and to request modules fairly fast.
• Shorten mtbbus_send_lock locked.

v1.0

Initial working production release.