Merge pull request #356 from cdburkard/patches/stop_controller

fix for controller shutdown - send SIGHUP rather than SIGKILL

mininet/node.py

@@ -205,7 +205,7 @@ def write( self, data ):
     def terminate( self ):
         "Send kill signal to Node and clean up after it."
         if self.shell:
-            os.killpg( self.pid, signal.SIGKILL )
+            os.killpg( self.pid, signal.SIGHUP )
         self.cleanup()
 
     def stop( self ):