CDAP-951 create tables in hive for any Table dataset created.

Start off with a fixed schema with plans to allow setting schema
in the near future. Also, Tables embedded within other datasets
are not yet supported due to wide ranging changes that would be
required for tracking instances of embedded datasets.

Added a storage handler and friends for CDAP tables. Unfortunately
we cannot re-use the HBaseStorageHandler because Tables are not
always HBase tables, like in Standalone mode.