UDP JSON Subscriber

I added a UDP JSON Subscriber. It receives JSON in UDP packets and adds the event. The types for everything are determined from the JSON packet, so you can setup this subscriber and send it all kinds of JSON packets and it will generate events for them without additional configuration needed.

I had written a unit test, but it throws a null pointer because there is no mocked version of the EPRuntime and I didn't want to bring Mockito into the project for just one unit test. I did have to bring 2 other dependencies in, and didn't have access to the parent pom to specify the version so I had to do so in-line.

I also fixed a minor bug in the FileSubscriber...

Thanks...

Bill-