Bugfixes:
  - Fix `TypeError: '_asyncio.Task' object is not callable` seen in logs
  - Fix pass-through of C bits in AX.25 addresses

Features:
  - Added APRS position report parsing and generation (except MIC-e)
  - Added native `asyncio`-based KISS interface support, support on
    other platforms (e.g. Windows Vista and later) should work better.
  - Added ability to serialise UI frames in TNC2 format for APRS-IS
    compatibility

Changes:
  - `nose`-based unit tests replaced with `py.test` due to a lack of
    upstream maintenance
  - Python 3.4 support dropped due it not supporting `async` / `await`
    and Python 3.10 not supporting `@coroutine`.  We say goodbye to the
    0 Windows XP users we had.

Known issues:
  - MIC-e traffic is not decoded or encoded by the APRS library
  - We don't handle APRS third-party traffic