* apps/morphers/recorder.hh
	(trait::image_< decorated_image<I,D> >): Replace with..
	(trait::image_< decorated_image<I, recorder<I> > >): ...this.
	Add a value_storage property.
	(ch_value_< decorated_image< image_<I>, data_< recorder<I> > >, V >):
	New trait, to handle changes of value types in images decorated
	with a recorder.
	* apps/morphers/mask+channel.cc,
	* apps/morphers/mask+recorder.cc,
	* apps/morphers/recorder.cc:
	Simplify these programs thanks to the preceding changes.