[SPARK-4553] [SPARK-5767] [SQL] Wires Parquet data source with the newly...

[SPARK-4553] [SPARK-5767] [SQL] Wires Parquet data source with the newly introduced write support for data source API

This PR migrates the Parquet data source to the new data source write support API.  Now users can also overwriting and appending to existing tables. Notice that inserting into partitioned tables is not supported yet.

When Parquet data source is enabled, insertion to Hive Metastore Parquet tables is also fullfilled by the Parquet data source. This is done by the newly introduced `HiveMetastoreCatalog.ParquetConversions` rule, which is a "proper" implementation of the original hacky `HiveStrategies.ParquetConversion`. The latter is still preserved, and can be removed together with the old Parquet support in the future.

TODO:

- [x] Update outdated comments in `newParquet.scala`.

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Author: Cheng Lian <lian@databricks.com>

Closes #4563 from liancheng/parquet-refining and squashes the following commits:

fa98d27 [Cheng Lian] Fixes test cases which should disable off Parquet data source
2476e82 [Cheng Lian] Fixes compilation error introduced during rebasing
a83d290 [Cheng Lian] Passes Hive Metastore partitioning information to ParquetRelation2