Add a boolean property that controls whether a window close button will be shown in the header bar or not. Doing this in the toolkit will ensure consistency of the visual apperance. https://bugzilla.gnome.org/show_bug.cgi?id=702971
https://bugzilla.gnome.org/show_bug.cgi?id=702996
As seen in GdHeaderBar.
This widget has been developed as GdHeaderBar in libgd. The copy here has been renamed and changed to use GTK+ internals.
