route: updates to name prefixes are more efficent.

With this change, only entries that have changed next-hops will
cause any change in the name prefix table.  Consequently, routing
table calculations no longer cause RIB registrations for unchanged
prefixes.  However, this is not a problem because FIB entries
refresh themselves.  This resulted in the removal of a test from the
TestNlsr suite.

refs: #2864

Change-Id: If28a04cb7bb47a3a6c32cd24578c68885d08d6b3
diff --git a/src/route/nexthop-list.cpp b/src/route/nexthop-list.cpp
index 97a89b0..903ca48 100644
--- a/src/route/nexthop-list.cpp
+++ b/src/route/nexthop-list.cpp
@@ -18,6 +18,7 @@
  * You should have received a copy of the GNU General Public License along with
  * NLSR, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
  **/
+
 #include "nexthop-list.hpp"
 #include "common.hpp"
 #include "nexthop.hpp"
@@ -61,6 +62,12 @@
   return true;
 }
 
+bool
+operator!=(const NexthopList& lhs, const NexthopList& rhs)
+{
+  return !(lhs == rhs);
+}
+
 std::ostream&
 operator<<(std::ostream& os, const NexthopList& nhl)
 {