Merge remote-tracking branch 'remotes/mdroth/tags/qga-pull-2016-07-25-tag' into staging

qemu-ga patch queue for 2.7

* fix w32 build failures due to -Werror when building with VSS/fsfreeze
  enabled
* fix leaking for qemu-ga config files in `make check`

# gpg: Signature made Mon 25 Jul 2016 20:01:09 BST
# gpg:                using RSA key 0x3353C9CEF108B584
# gpg: Good signature from "Michael Roth <flukshun@gmail.com>"
# gpg:                 aka "Michael Roth <mdroth@utexas.edu>"
# gpg:                 aka "Michael Roth <mdroth@linux.vnet.ibm.com>"
# Primary key fingerprint: CEAC C9E1 5534 EBAB B82D  3FA0 3353 C9CE F108 B584

* remotes/mdroth/tags/qga-pull-2016-07-25-tag:
  configure: mark qemu-ga VSS includes as system headers
  tests: use static qga config file
  build-sys: link tests/data

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