Merge remote-tracking branch 'remotes/mdroth/tags/qga-pull-2019-03-18-tag' into staging

Merge remote-tracking branch 'remotes/mdroth/tags/qga-pull-2019-03-18-tag' into staging

qemu-ga patch queue for 4.0

* fix w32 build breakages with VSS enabled
* fix PCI topology reporting for Windows
* fix OS version reporting for Windows
* add systemd info to qga schema documentation
* add proper 'id' handling to QGA so it conforms to QMP spec

# gpg: Signature made Mon 18 Mar 2019 16:20:32 GMT
# gpg:                using RSA key CEACC9E15534EBABB82D3FA03353C9CEF108B584
# gpg:                issuer "mdroth@linux.vnet.ibm.com"
# gpg: Good signature from "Michael Roth <flukshun@gmail.com>" [full]
# gpg:                 aka "Michael Roth <mdroth@utexas.edu>" [full]
# gpg:                 aka "Michael Roth <mdroth@linux.vnet.ibm.com>" [full]
# Primary key fingerprint: CEAC C9E1 5534 EBAB B82D  3FA0 3353 C9CE F108 B584

* remotes/mdroth/tags/qga-pull-2019-03-18-tag:
  qmp: common 'id' handling & make QGA conform to QMP spec
  qga: process_event() simplification
  qga: Fix guest-get-fsinfo PCI address collection in Windows
  qga-win: fix VSS build breakage due to unintended gnu99 C++ flag
  qga-win: include glib when building VSS DLL
  qga-win: Adding support for Windows Server 2019 get-osinfo command
  qga: update docs with systemd suspend support info

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