Merge remote-tracking branch 'luiz/queue/qmp' into staging

Merge remote-tracking branch 'luiz/queue/qmp' into staging

# By Kevin Wolf (4) and others
# Via Luiz Capitulino
* luiz/queue/qmp:
  add timestamp to error_report()
  qapi-schema: Use existing type for drive-backup arguments
  qapi-schema: Use BlockdevSnapshot type for blockdev-snapshot-sync
  qapi.py: Allow top-level type reference for command definitions
  qapi.py: Avoid code duplication
  qemu-char: Fix ringbuf option size

Message-id: 1373478767-20965-1-git-send-email-lcapitulino@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>