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'm good with where they live. At some point when we need to support other tools, we'll have to do quite a bit of refactoring or having duplicated code. I had a version of  an example that attempted to re-use the CLI code for a custom tool and it was basically impossible to make use of the base classes.