[WIP][SPARK-2406][SQL] Initial support for using ParquetTableScan to read HiveMetaStore tables.

This PR adds an experimental flag `spark.sql.hive.convertMetastoreParquet` that when true causes the planner to detects tables that use Hive's Parquet SerDe and instead plans them using Spark SQL's native `ParquetTableScan`.
I think we are okay as long as we don't use createQueryTest anywhere, since it runs `reset()`.  I can try to move the DDL into each test to be safe though.