gtk: drop gtk_widget_set_double_buffered call

Dunno why it is here.  Removing it seems to have no ill side effects.
It is depricated in 3.14+.  In some cases it has no effect since 3.10
according to the docs:

https://developer.gnome.org/gtk3/stable/GtkWidget.html#gtk-widget-set-double-buffered

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
gtk: avoid gd_widget_reparent with gtk 3.14+

gtk_widget_reparent is depricated in gtk 3.14, stop using it.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Merge remote-tracking branch 'remotes/kraxel/tags/pull-gtk-20141028-1' into staging

gtk: fix two warnings with gtk 3.14+

# gpg: Signature made Tue 28 Oct 2014 10:25:52 GMT 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-20141028-1:
  gtk: avoid gd_widget_reparent with gtk 3.14+
  gtk: drop gtk_widget_set_double_buffered call

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