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.
Before my uncommitted changes, the defaults are empty and it just defaults to what Flume uses. I think it's far more useful to force a user to think about what those values should be when they first use the command. I don't think it's a safe assumption that users will edit the configuration files prior to attempting to use them. I think our docs are just as capable of explaining the options as the Flume docs and the descriptions from help are sufficient to prompt recall or encourage someone to go check the more detailed docs if they're confused.

If we provide default values, then the user is much more likely to miss them even if we try to prompt them with an edit location in the generated file.