stubbed in drop wizard ingestion.
a little bit of cleanup.
Ingest raw metrics.

* FakeMetricsWriter so that writes are a noop. Specified in IngestConfiguration.
* Plumb IMetricsWriter and ScheduleContext into BasicIngestResource and Application.
* Add optional units field to BasicMetric.
Immutable response for basic ingest
Ingest support for aggregated metrics (including multi-tenant)
fix aggregated bugs:

* gauge was declaring a duplicate json field.
* percentile definition did not match expected data
Add a readme
port over a few more properties from the default blueflood configuration.
Wire up shard state management.
enforce tenant control for scoped ingestion.
add hooks for metric pre- and post-processing.
Legacy metric ingestion.

 - caches type, units and rollup type.

 Mostly a POC. It does not handle multi-tenant or aggregated metrics.
be more friendly to cassandra 2.x - lower case keyspaces.
import the datastax java driver.