* doc/Doxyfile.in: add a new macro.

	* doc/Makefile.am: add new distributed files.

	* doc/examples/tuto3/first_routine.cc: add doxygen file tag.

	* doc/groups.hh,
	* doc/groups/accu.hh,
	* doc/groups/functions.hh,
	* doc/groups/graph.hh,
	* doc/groups/images.hh,
	* doc/groups/main.hh,
	* doc/groups/neighb.hh,
	* doc/groups/site_set.hh,
	* doc/groups/util.hh,
	* doc/groups/win.hh,
	* mln/accu/bbox.hh,
	* mln/accu/center.hh,
	* mln/accu/convolve.hh,
	* mln/accu/count.hh,
	* mln/accu/count_adjacent_vertices.hh,
	* mln/accu/count_labels.hh,
	* mln/accu/height.hh,
	* mln/accu/histo.hh,
	* mln/accu/inf.hh,
	* mln/accu/internal/couple.hh,
	* mln/accu/label_used.hh,
	* mln/accu/land.hh,
	* mln/accu/land_basic.hh,
	* mln/accu/line.hh,
	* mln/accu/lor.hh,
	* mln/accu/lor_basic.hh,
	* mln/accu/maj_h.hh,
	* mln/accu/max.hh,
	* mln/accu/max_h.hh,
	* mln/accu/mean.hh,
	* mln/accu/median_alt.hh,
	* mln/accu/median_h.hh,
	* mln/accu/min.hh,
	* mln/accu/min_h.hh,
	* mln/accu/min_max.hh,
	* mln/accu/pair.hh...