Added nDPId semantic validation test.

* fixed inconsistent processing of remaining flows during nDPId shutdown phase
 * fixed multiple `detected' flow events
   (instead only `detection-update' flow events can occur after a `detected' flow event)
 * fixed nDPIsrvd.py invalid message buffer handling
 * improved run_tests.sh so only valid pcap capture files are getting processed
   (and some more cosmetics + logging)

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

examples/py-schema-validation/py-schema-validation.py

@@ -48,3 +48,5 @@ if __name__ == '__main__':
         nsock.loop(onJsonLineRecvd, Stats())
     except nDPIsrvd.SocketConnectionBroken as err:
         sys.stderr.write('\n{}\n'.format(err))
+    except KeyboardInterrupt:
+        print()