* tests/median.cc: Update.
	* mln/convert/to_dpoint.hh: New.
	* mln/debug/println.hh (println): Add endl.
	* mln/level/median.hh: New.
	* mln/io/save_pgm.hh: New.
	* mln/io/load_pgm.hh: New.
	* mln/core/box.hh (len): New.
	* mln/core/concept/box.hh: Likewise.
	* mln/core/point.hh (zero): New.
	* mln/core/dpoint.hh: Likewise.
	* mln/core/concept/window.hh (dpoint, point): New.
	* mln/core/window.hh,
	* mln/core/rectangle2d.hh: Update.
	* mln/core/concept/genpoint.hh: Remove dead line.
	* mln/core/concept/dpoint.hh (operator+): New.
	* mln/core/image2d_b.hh: .
	* mln/core/internal/force_exact.hh: Avoid obj creation.
	* mln/accu: New.
	* mln/value/histo.hh: Rename as...
	* mln/value/median.hh: ...this.
	* mln/accu/histo.hh: Rename as...
	* mln/accu/median.hh: ...this.
	* mln/accu/median_alt.hh: New.


git-svn-id: https://svn.lrde.epita.fr/svn/oln/trunk@1005 4aad255d-cdde-0310-9447-f3009e2ae8c0