Merge remote-tracking branch 'remotes/mdroth/tags/qga-pull-2016-04-07-tag' into staging

qemu-ga patch queue for 2.6

* fix w32 bug where output from guest-exec is not properly captured
* fix w32 bug where FDs are leaked after guest-exec is invoked

# gpg: Signature made Thu 07 Apr 2016 17:46:21 BST using RSA key ID F108B584
# gpg: Good signature from "Michael Roth <[email protected]>"
# gpg:                 aka "Michael Roth <[email protected]>"
# gpg:                 aka "Michael Roth <[email protected]>"

* remotes/mdroth/tags/qga-pull-2016-04-07-tag:
  qga: Workaround for console redirection from non-interactive qemu-ga service
  qga: fix fd leak with guest-exec i/o channels

Signed-off-by: Peter Maydell <[email protected]>