Merge remote-tracking branch 'remotes/kraxel/tags/pull-gtk-20141104-2' into staging

gtk: fix fullscreen with gtk3, fix build with older gtk2 versions.

# gpg: Signature made Tue 04 Nov 2014 13:42:09 GMT using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <[email protected]>"
# gpg:                 aka "Gerd Hoffmann <[email protected]>"
# gpg:                 aka "Gerd Hoffmann (private) <[email protected]>"

* remotes/kraxel/tags/pull-gtk-20141104-2:
  gtk: add GDK_KEY_pause #define
  gtk: Hide the menubar when in fullscreen mode (lp 1294898)
  gtk: Install vc accelerators on parent window
  gtk: Install fullscreen accelerator on toplevel window
  gtk: Grab accel_group from GtkDisplayState

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