* img/lena.pbm: lena in pbm
	* img/lena.ppm: lena in ppm
	* mln/convert/to_rgb.hh: operation to convert
		some values to rgb in order to make pgm::load<rgb8>
		compile
	* mln/io/pbm/load.hh:
		load a pbm image into an image2d_b<bool>
	* mln/io/pbm/save.hh: New.
		save an image2d_b<bool> into a pbm image file
	* mln/io/pbm: New.
	* mln/io/pgm/load.hh:
		add 16 bits handling
	* mln/io/pgm/save.hh:
		add 16 bits handling
	* mln/io/ppm/load.hh: New.
		load a ppm image into an image2d_b<rgb8>
	* mln/io/ppm/save.hh: New.
		save an image2d_b<rgb8> into a ppm image file
	* mln/io/ppm: New directory.
	* mln/value/int_u.hh:
		fix to compile with the good flags
	* mln/value/rgb.hh:
		update of rgb values
	* tests/io_pbm.cc:
		a test
	* tests/io_pgm.cc:
		a test
	* tests/io_pgm16.cc:
		a test
	* tests/io_ppm.cc:
		a test

git-svn-id: https://svn.lrde.epita.fr/svn/oln/trunk@1104 4aad255d-cdde-0310-9447-f3009e2ae8c0