Make FSF addresses in COPYING be URLs.

COPYING

@@ -1,8 +1,7 @@
 		  GNU LESSER GENERAL PUBLIC LICENSE
 		       Version 2.1, February 1999
 
- Copyright (C) 1991, 1999 Free Software Foundation, Inc.
-     51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ Copyright (C) 1991, 1999 Free Software Foundation, Inc. <http://fsf.org/>
  Everyone is permitted to copy and distribute verbatim copies
  of this license document, but changing it is not allowed.
 
@@ -484,8 +483,7 @@ convey the exclusion of warranty; and each file should have at least the
     Lesser General Public License for more details.
 
     You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+    License along with this library; if not, see <http://www.gnu.org/licenses/>.
 
 Also add information on how to contact you by electronic and paper mail.