Revert "CDK-177. Change Flume Log4jAppender to use Marker instead of PartitionKey."

This reverts commit 9699fd9b9fd230bc77562704f6d532f60331126f.
Revert "CDK-177. Add convenience for exposing a View as a Crunch ReadableSource."

This reverts commit fd23f601254dc8ebb81bbf9d3a557093914a1539.