virtainer-guest-agent 0.4.0

• Windows: __io.virtainer_shell is supported. It runs Windows PowerShell
  as SYSTEM on a pseudo console (ConPTY), with the same frames, resize and
  exit report as on Linux; the only user accepted is SYSTEM. Ctrl-C
  reaches the foreground program, output is UTF-8, and ending the session
  ends every process the shell started. As on Linux, at most 8 sessions run
  at once, apart from the 16 QGA connections, a session has no idle timeout,
  and blocking guest-exec blocks the Shell too.