NSCL license

[Libor Polčák]

Hello Giorgio,

it seems that NSCL is lacking headers specifying the license and AFAIK it is 
not clear if the library is using GPL3 or GPL3+.

You might want to add text like below to each source code file:

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

I plan to close https://github.com/polcak/jsrestrictor/pull/87 soon. If you 
want, I can try to add the missing headers using REUSE also to NSCL.

Btw any objection against modifying JSR headers with REUSE (I do not want to 
produce unnecessary conflicts.

Libor