Make 'batchSize' configurable, add a gauge.

In order to determine the effect of changing the batch size for the HBase, we
need to be able to modify it, ideally without re-compiling each time.  This
commit adds the ability to specify the batch size as a run-time parameter.

We also add a gauge so that we can check the current value of batch size at
run time, giving us a denominator to make sense of the flush times.
Add the batch size param to one consumer
Add a Console Reporter for metrics output
Add a "replay" consumer

This consumer reads from a kafka queue, re-creates the original
requests, and submits them as new HTTP requests.

It is intended to help in testing the stage environment using
production data.

This inital version supports optional sampling of the queued records and
the ability to generate new keys for each request or copy the source keys.
Add support for delete.
Add a config setting to control replaying deletes.
Fixed the required/optional args.

The 'dest' arg of KafkaReplayConsumer should be mandatory, and the other ones
should all be optional.
Add metrics for delete failures.
Make the LoggerSink output more greppable

Add the method name/description as a prefix to the log output, so that it's
easier to filter for the the stuff you're interested in (my use case was to
filter out just the deleted IDs).
Merge branch 'more_delete_metrics' into mreid-0.9
Merge branch 'prod_to_stage_replay_consumer' into mreid-0.9
Merge branch 'configurable_batch_size' into mreid-0.9

Conflicts:
	src/main/java/com/mozilla/bagheera/sink/HBaseSink.java
Remove a 'done' TODO
Restore default batchSize for FHR Consumer.
Merge pull request #13 from mozilla-metrics/mreid-0.9

Recent changes to improve monitoring, configurability, and testability