CDK-514: Update dataset-staging.

The example now uses Datasets.load and views rather than partitions. The
StagingToPersistent task is now quite a bit smaller.
CDK-514: Update dataset example.

This updates the example to use Datasets and views. It also changes
logging so that the Avro file reader's debug messages can be used to
demonstrate that only one partition is read in the partitioning section.

Partitioning is now demonstrated with favoriteColor rather than by a
hash partitioner. This is easier to understand and demonstrates the
storage layout more clearly.
CDK-514: Update dataset-compatibility.

Passing a location to a dataset now works, so this loads data into HDFS
and creates datasets that point to it. Also moved to the Datasets API
and removed reader.open().
CDK-514: Update dataset-hbase example.

Uses the Datasets API.
Use UTC for timestamps for avoid timezone issues.
Address review comments.
CDK-514: Update examples for CDK-511.

This removes all of the unnecessary type parameters for Datasets
methods.