ToolItemGroup: Wrap child properties

	* gtk/src/gtk_signals.defs: Add definitions for "homogeneous",
	"expand", "fill", "new-row", and "position" child properties.
	* gtk/src/toolitemgroup.hg: Add wrappers for the aforementioned
	child properties.
	* See https://bugzilla.gnome.org/show_bug.cgi?id=140515
Layout: Wrap child properties

	* gtk/src/gtk_signals.defs: Add definitions for "x" and "y"
	child properties.
	* gtk/src/layout.hg: Add wrappers for the aforementioned child
	properties.
	* See https://bugzilla.gnome.org/show_bug.cgi?id=140515