This PR updates PR #6135 authored by zhzhan from Hortonworks.

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This PR implements a Spark SQL data source for accessing ORC files.

> **NOTE**
>
> Although ORC is now an Apache TLP, the codebase is still tightly coupled with Hive.  That's why the new ORC data source is under `org.apache.spark.sql.hive` package, and must be used with `HiveContext`.  However, it doesn't require existing Hive installation to access ORC files.

1.  Saving/loading ORC files without contacting Hive metastore

1.  Support for complex data types (i.e. array, map, and struct)

1.  Aware of common optimizations provided by Spark SQL:

    - Column pruning
    - Partitioning pruning
    - Filter push-down

1.  Schema evolution support
1.  Hive metastore table conversion

This PR also include initial work done by scwf from Huawei (PR #3753).

Author: Zhan Zhang <zhazhan@gmail.com>
Author: Cheng Lian <lian@databricks.com>

Closes #6194 from liancheng/polishing-orc and squashes the following commits:

55ecd96 [Cheng Lian] Reorganizes ORC test suites
d4afeed [Cheng Lian] Addresses comments
21ada22 [Cheng Lian] Adds @since and @Experimental annotations
128bd3b [Cheng Lian] ORC filter bug fix
d734496 [Cheng Lian] Polishes the ORC data source
2650a42 [Zhan Zhang] resolve review comments
3c9038e [Zhan Zhang] resolve review comments
7b3c7c5 [Zhan Zhang] save mode fix
f95abfd [Zhan Zhang] reuse test suite
7cc2c64 [Zhan Zhang] predicate fix
4e61c16 [Zhan Zhang] minor change
305418c [Zhan Zhang] orc data source support