Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-07-19' into staging

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-07-19' into staging

QAPI patches for 2016-07-19

# gpg: Signature made Tue 19 Jul 2016 19:35:27 BST
# 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-2016-07-19:
  net: Use correct type for bool flag
  qapi: Change Netdev into a flat union
  block: Simplify drive-mirror
  block: Simplify block_set_io_throttle
  qapi: Implement boxed types for commands/events
  qapi: Plumb in 'boxed' to qapi generator lower levels
  qapi-event: Simplify visit of non-implicit data
  qapi: Drop useless gen_err_check()
  qapi: Add type.is_empty() helper
  qapi: Hide tag_name data member of variants
  qapi: Special case c_name() for empty type
  qapi: Require all branches of flat union enum to be covered
  net: use Netdev instead of NetClientOptions in client init
  qapi: change QmpInputVisitor to QSLIST
  qapi: change QmpOutputVisitor to QSLIST

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