Update FSF address and fix UTF8

Update FSF address and fix UTF8

- Update FSF address in COPYRIGHT
  old: 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
  new: 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- Update LICENSE file according to the current version from:
  https://www.gnu.org/licenses/gpl-2.0.txt
- Update bindings/python/COPYING according to the current version from:
  https://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt
- Change encoding of CONTRIBUTORS from ISO 8859-1 to UTF-8
- Fixes rpmlint warnings and errors:
  W: file-not-utf8 CONTRIBUTORS
  E: incorrect-fsf-address COPYRIGHT
  E: incorrect-fsf-address LICENSE
  E: incorrect-fsf-address bindings/python/COPYING