Merge remote-tracking branch 'mdroth/qga-pull-5-15-12' into staging

Merge remote-tracking branch 'mdroth/qga-pull-5-15-12' into staging

* mdroth/qga-pull-5-15-12:
  qemu-ga: align versioning with QEMU_VERSION
  qemu-ga: fix segv after failure to open log file
  qemu-ga: guest-shutdown: use only async-signal-safe functions
  qemu-ga: guest-shutdown: become synchronous
  qemu-ga: guest-suspend: make the API synchronous
  qemu-ga: become_daemon(): reopen standard fds to /dev/null
  qemu-ga: make reopen_fd_to_null() public
  qemu-ga: guest-suspend-hybrid: don't emit a success response
  qemu-ga: guest-suspend-ram: don't emit a success response
  qemu-ga: guest-suspend-disk: don't emit a success response
  qemu-ga: guest-shutdown: don't emit a success response
  qemu-ga: don't warn on no command return
  qapi: add support for command options