Rename fraction directory into frac directory.

	* green/doc/examples/fraction/frac.cc        : Delete.
	* green/doc/examples/fraction/frac.hh        : Delete.
	* green/doc/examples/fraction/gcd.hh         : Delete
	* green/doc/examples/fraction/sign_prod.hh   : Delete.

	* green/doc/examples/frac/frac.cc            : New.
	* green/doc/examples/frac/frac.hh            : New.
	* green/doc/examples/frac/gcd.hh             : New.
	* green/doc/examples/frac/sign_prod.hh       : New.
	* green/doc/examples/frac/Makefile.am        : New.

	Collect some tmp results.

	* green/mln/io/plot/save_histo_sh.hh
	(save_histo_sh<2d>)            : Comment method.
	* green/mln/mln/accu/stat/histo1d.hh
	                               : Update documentation.
	* green/mln/mln/accu/stat/histo3d_rgb.hh
	                               : Update documentation.
	* green/mln/mln/accu/stat/histo3d_hsl.hh
	                               : Update documentation.
	* green/mln/tests/accu/stat/histo1d/histo1d.cc
	(test_8bits_integration, main) : Comment unused code, save tmp results.
	(test_8bits_operator_equal)    : Test infer "!=" operator.
	* green/mln/tests/accu/stat/histo3d_rgb/histo3d_rgb.cc
	(test_integration, main)       : Comment unused code, save tmp results.
	* green/mln/tests/accu/stat/histo3d_hsl/histo3d_hsl.cc
	(test_integration, main)       : Comment unused code, save tmp results.

git-svn-id: https://svn.lrde.epita.fr/svn/oln/trunk@4528 4aad255d-cdde-0310-9447-f3009e2ae8c0