Merge remote-tracking branch 'remotes/qmp-unstable/queue/qmp' into staging

Merge remote-tracking branch 'remotes/qmp-unstable/queue/qmp' into staging

* remotes/qmp-unstable/queue/qmp:
  docs/qmp: Fix documentation of BLOCK_JOB_READY to match code
  char: report frontend open/closed state in 'query-chardev'
  virtio-serial: report frontend connection state via monitor
  qmp: add qmp-events.txt back
  qapi event: clean up in callers
  qapi script: clean up in scripts
  qapi: ignore generated event files
  qapi: move event defines

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>