CDK-604: Added commands to generate logging and Flume configs

* The Flume configuration defaults to an AvroSource listening on 0.0.0.0:41415
* The Flume configuration defaults to a file channel
* The log4j configuration defaults to writing to port 41415, but requires the hostname
* The log4j configuration requires a package or class name to log to Flume, or a
  switch of --log-all to configure the rootLogger.
* Besides the unit tests, I ran some manual tests on a cluster by completing the
  logging example, but using the tool derived configs rather than the ones that
  shipped with the example.
I agree that logging-config is too general. Plus what we are configuring isn't dataset logging, it is using a logging infrastructure to magically send objects to Flume. That's a really weird way of sending data in my opinion. I know it's useful and we do it all the time, but I think it at least warrants a name that is more clear.

I'm also wondering if we shouldn't have a separate kite-config command for generating configuration files. I want to keep the dataset command focused on dataset tasks and not have a huge list of available commands. What do you guys think about creating kite-config-tool and kite-data-tool modules?