Improve a warning.

Improve a warning.

	* gtk/gtkcontainer.c (gtk_container_class_install_child_property):
	Improve a warning.

	* gdk/linux-fb/gdkinput.c (gdk_device_get_axis): Remove a broken
	and redundant doc comment.

	* gtk/gtkprogress.c (gtk_progress_class_init):
	* gtk/gtkprogressbar.c (gtk_progress_bar_class_init):
	* gtk/gtktexttag.c (gtk_text_tag_class_init):
	* gtk/gtknotebook.c (gtk_notebook_class_init): Better blurbs,
	incorporating stuff from the doc templates.

	* gtk/gtkplug.c (gtk_plug_construct): Fix docs.