Add message when kernel catches KeyboardInterrupt.

IPython/zmq/ipkernel.py

@@ -172,7 +172,7 b' class Kernel(Configurable):'
                 self.do_one_iteration()
             except KeyboardInterrupt:
                 # Ctrl-C shouldn't crash the kernel
-                continue
+                io.raw_print("KeyboardInterrupt caught in kernel")
 
     def record_ports(self, xrep_port, pub_port, req_port, hb_port):
         """Record the ports that this kernel is using.