Add header and license notice on all files

The useful script : 

    #! /bin/bash
    #
    # add_header.sh
    #
    # Copyright © 2014 Mathieu Gaborit (matael) <mathieu@matael.org>
    #
    #
    # Distributed under WTFPL terms
    #
    #            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
    #                    Version 2, December 2004
    #
    # Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
    #
    # Everyone is permitted to copy and distribute verbatim or modified
    # copies of this license document, and changing it is allowed as long
    # as the name is changed.
    #
    #            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
    #   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
    #
    #  0. You just DO WHAT THE FUCK YOU WANT TO.
    #
    
    
    generic_header="%\n% Copyright (C) 2014 < Olivier DAZEL <olivier.dazel@univ-lemans.fr> >\n%\n% This file is part of PLANES.\n%\n% PLANES (Porous LAum NumErical Simulator) is a software to compute the\n% vibroacoustic response of sound packages containing coupled\n% acoustic/elastic/porous substructures.  It is mainly based on the\n% Finite-Element Method and some numerical methods developped at\n% LAUM (http://laum.univ-lemans.fr).\n%\n% You can download the latest version of PLANES at\n%                 https://github.com/OlivierDAZEL/PLANES\n% or find more details on Olivier's webpage\n%                 http://perso.univ-lemans.fr/~odazel/\n%\n% For any questions or if you want to\n% contribute to this project, contact Olivier.\n%\n% PLANES is free software: you can redistribute it and/or modify\n% it under the terms of the GNU General Public License as published by\n% the Free Software Foundation, either version 3 of the License, or\n% (at your option) any later version.\n%\n% This program is distributed in the hope that it will be useful,\n% but WITHOUT ANY WARRANTY; without even the implied warranty of\n% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n% GNU General Public License for more details.\n%\n% You should have received a copy of the GNU General Public License\n% along with this program.  If not, see <http://www.gnu.org/licenses/>.\n%%\n\n"


    tmpfile="content_tmp"
    orig=$PWD
    for dir in $(find ./ -type d); do
    	cd $dir
    	for f in *.m*; do
    		if [[ "${f:$((${#str}-1)):1}" == "~" ]]; then
    			filename="${f::-1}"
    		else
    			filename="$f"
    		fi
    		echo "Working on $dir/$f"
    		cp $f $tmpfile
    		echo "% $filename" > $f
    		echo -e $generic_header >> $f
    		cat $tmpfile>> $f
    	done
    	rm $tmpfile
    	cd $orig
    done