Merge remote-tracking branch 'remotes/kraxel/tags/pull-gtk-20150915-1' into staging

gtk: misc grab tweaks, locale fix.

# gpg: Signature made Tue 15 Sep 2015 11:35:36 BST using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-gtk-20150915-1:
  gtk: use setlocale() for LC_MESSAGES only
  gtk: don't grab input when entering fullscreen.
  gtk: set free_scale when setting zoom_fit
  gtk: trace input grab reason
  gtk: move gd_update_caption calls to gd_{grab,ungrab}_{pointer,keyboard}
  gtk: check for existing grabs in gd_grab_{pointer,keyboard}

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