* oln/automatic/image_having_neighborhood.hh: Add a forward
	declaration of oln::abstract::image_having_neighborhood.
	(impl<abstract::image_having_neighborhood, morpher::tag::identity, E>):
	Inherit from abstract::image<E>.
	(impl_neighborhood): Make it const.
	Get the exact type before calling delegate().
	* oln/core/abstract/image_having_neighborhood.hh
	(oln/automatic/image_having_neighborhood.hh): Include it.
	(oln::abstract::image_having_neighborhood::neighborhood): New.
	(case_<image_hierarchy_wrt_neighborhood, E, 1>): Only inherit from
	oln::abstract::image_having_neighborhood if neighborhood is
	different from mlc::not_found.
	(oln::ext_vtype<image_entry<E>, typedef_::neighborhood_type>):
	Remove.
	* oln/core/image_entry.hh
	(single_vtype<image_entry<E>, typedef_::morpher_type>): Remove.
	Instead, defined the `morpher' virtual type...
	(vtypes< image_entry<E> >): ...here.

	* oln/morpher/internal/image_extension.hh (image_extension):
	Fix the inheritance: derive from `oln::image_entry<Exact>' instead
	of `oln::image_entry< image_extension<Image, Exact> >'.
	* oln/morpher/identity.hh (oln/morpher/tags.hh): Include it.
	(oln::single_vtype<morpher::identity<Image>, typedef_::morpher_type>):
	Remove.
	Instead, defined the `morpher' virtual type...
	(oln::vtypes< morpher::identity<Image> >): ...here
	(oln::morpher::tag::identity): Move...
	* oln/morpher/tags.hh: ...here (new file).
	* oln/morpher/add_neighborhood.hh (oln/morpher/tags.hh)
	(oln/core/2d/aliases.hh): Include them.
	(oln::single_vtype<morpher::add_neighborhood<Image>,
	 typedef_::morpher_type>): Remove.
	Instead, defined the `morpher' virtual type...
	(oln::vtypes< morpher::add_neighborhood<Image> >): ...here
	(oln::morpher::add_neighborhood::neighborhood_t): Fix the virtual
	type retrieval: get it from `self_t', not from `Image'.
	(ext_vtype<morpher::add_neighborhood< oln::image2d<T> >,
	 typedef_::neighborhood_type>): Remove.
	Remove corresponding forward declarations as well.
	(oln::morpher::tag::add_neighborhood): Move...
	* oln/morpher/tags.hh: ...here.
	* tests/identity_morpher.cc, tests/morphers.cc: Fix the test.
	Add more static assertions.

	* oln/Makefile.am (nobase_oln_HEADERS): Add core/2d/neighb2d.hh,
	core/abstract/neighborhood.hh, core/gen/neighb.hh and
	core/neighborhood_entry.hh.
	* oln/core/2d/image2d.hh: Fix copyright header.


git-svn-id: https://svn.lrde.epita.fr/svn/oln/trunk@555 4aad255d-cdde-0310-9447-f3009e2ae8c0