[SPARK-6923] [SPARK-7550] [SQL] Persists data source relations in Hive...

[SPARK-6923] [SPARK-7550] [SQL] Persists data source relations in Hive compatible format when possible

This PR is a fork of PR #5733 authored by chenghao-intel.  For committers who's going to merge this PR, please set the author to "Cheng Hao <hao.chengintel.com>".

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When a data source relation meets the following requirements, we persist it in Hive compatible format, so that other systems like Hive can access it:

1. It's a `HadoopFsRelation`
2. It has only one input path
3. It's non-partitioned
4. It's data source provider can be naturally mapped to a Hive builtin SerDe (e.g. ORC and Parquet)

Author: Cheng Lian <lian@databricks.com>
Author: Cheng Hao <hao.cheng@intel.com>

Closes #7967 from liancheng/spark-6923/refactoring-pr-5733 and squashes the following commits:

5175ee6 [Cheng Lian] Fixes an oudated comment
3870166 [Cheng Lian] Fixes build error and comments
864acee [Cheng Lian] Refactors PR #5733
3490cdc [Cheng Hao] update the scaladoc
6f57669 [Cheng Hao] write schema info to hivemetastore for data source