all: update license headers to distiguish GPL/LGPL

All code outside of cmd/ is licensed as LGPL. The headers
now reflect this by calling the whole work "the go-ethereum library".

cmd/geth/js.go

@@ -8,11 +8,11 @@
 //
 // go-ethereum 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
+// 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 go-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
 
 package main