* mln/algebra/all.hh: fix comments.

	* mln/algebra/vec.hh: add operator>>.

	* mln/core/internal/graph_psite_base.hh: convert to the correct id
	type.

	* mln/debug/draw_graph.hh: update doc.

	* mln/graph/all.hh,
	* mln/graph/essential.hh: new headers.

	* mln/all.hh,
	* mln/essential/routine.hh: include new headers.

	* mln/io/pnm/load.hh: fix load_ascii builtin.

	* mln/make/edge_image.hh: update prototype.

	* mln/make/vertex_image.hh: be less restrictive on the function type.

	* tests/level/approx/median.cc,
	* tests/level/median.cc,
	* tests/level/naive/median.cc: use a smaller image.

	* tests/make/dummy_p_vertices.cc: test element id.

git-svn-id: https://svn.lrde.epita.fr/svn/oln/trunk@3731 4aad255d-cdde-0310-9447-f3009e2ae8c0