Merge remote-tracking branch 'remotes/armbru/tags/pull-monitor-2018-12-12' into staging

Merge remote-tracking branch 'remotes/armbru/tags/pull-monitor-2018-12-12' into staging

Monitor patches for 2018-12-12

# gpg: Signature made Wed 12 Dec 2018 10:08:15 GMT
# gpg:                using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-monitor-2018-12-12:
  tests: add oob functional test for test-qmp-cmds
  Revert "tests: Add parameter to qtest_init_without_qmp_handshake"
  monitor: Remove "x-oob", offer capability "oob" unconditionally
  monitor: Suspend monitor instead dropping commands
  monitor: avoid potential dead-lock when cleaning up
  monitor: prevent inserting new monitors after cleanup
  colo: check chardev can switch context
  monitor: check if chardev can switch gcontext for OOB
  char: add a QEMU_CHAR_FEATURE_GCONTEXT flag
  monitor: accept chardev input from iothread
  monitor: inline ambiguous helper functions

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