Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-10-15' into staging

QAPI patches

# gpg: Signature made Thu 15 Oct 2015 07:40:46 BST using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2015-10-15:
  qapi: Track location that created an implicit type
  qapi: Create simple union type member earlier
  qapi: Lazy creation of array types
  qapi: Don't use info as witness of implicit object type
  qapi: Drop redundant args-member-array test
  qapi: Drop redundant flat-union-reverse-define test
  qapi: Drop redundant returns-int test
  qapi: Move empty-enum to compile-time test
  qapi: Drop redundant alternate-good test
  qapi: Prepare for errors during check()
  qapi: Use predicate callback to determine visit filtering
  qapi: Fix regression with '-netdev help'

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