Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-02-28' into staging

QAPI patches for 2017-02-28

# gpg: Signature made Sun 05 Mar 2017 08:21:51 GMT
# gpg:                using RSA key 0x3870B400EB918653
# 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-qapi-2017-02-28: (27 commits)
  qapi: Improve qobject visitor documentation
  qapi: Fix object input visit beyond end of list
  tests: Cover input visit beyond end of list
  qapi: Make input visitors detect unvisited list tails
  test-qobject-input-visitor: Cover missing nested struct member
  tests: Cover partial input visit of list
  test-string-input-visitor: Improve list coverage
  test-string-input-visitor: Tear down existing test automatically
  tests-qobject-input-strict: Merge into test-qobject-input-visitor
  qapi: Drop unused non-strict qobject input visitor
  test-qobject-input-visitor: Use strict visitor
  qom: Make object_property_set_qobject()'s input visitor strict
  qapi: Make string input and opts visitor require non-null input
  qapi: Drop string input visitor method optional()
  qapi: Improve qobject input visitor error reporting
  qapi: Make QObject input visitor set *list reliably
  qapi: Clean up after commit 3d344c2a
  qapi: Improve a QObject input visitor error message
  qmp: Eliminate silly QERR_QMP_* macros
  qmp: Drop duplicated QMP command object checks
  ...

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