Merge remote-tracking branch 'remotes/ericb/tags/pull-qapi-2018-03-01-v4' into staging

Merge remote-tracking branch 'remotes/ericb/tags/pull-qapi-2018-03-01-v4' into staging

qapi patches for 2018-03-01

- Markus Armbruster: Modularize generated QAPI code

# gpg: Signature made Fri 02 Mar 2018 19:50:16 GMT
# gpg:                using RSA key A7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg:                 aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-qapi-2018-03-01-v4: (30 commits)
  qapi: Don't create useless directory qapi-generated
  Fix up dangling references to qmp-commands.* in comment and doc
  qapi: Move qapi-schema.json to qapi/, rename generated files
  docs: Correct outdated information on QAPI
  docs/devel/writing-qmp-commands: Update for modular QAPI
  qapi: Empty out qapi-schema.json
  Include less of the generated modular QAPI headers
  qapi: Generate separate .h, .c for each module
  watchdog: Consolidate QAPI into single file
  qapi/common: Fix guardname() for funny filenames
  qapi/types qapi/visit: Generate built-in stuff into separate files
  qapi: Make code-generating visitors use QAPIGen more
  qapi: Rename generated qmp-marshal.c to qmp-commands.c
  qapi: Record 'include' directives in intermediate representation
  qapi: Generate in source order
  qapi: Record 'include' directives in parse tree
  qapi: Concentrate QAPISchemaParser.exprs updates in .__init__()
  qapi: Lift error reporting from QAPISchema.__init__() to callers
  qapi/common: Eliminate QAPISchema.exprs
  qapi: Improve include file name reporting in error messages
  ...

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