Create a jackson integration module for pojo support

There's currently a PR for pojo support:
https://github.com/apache/incubator-parquet-mr/pull/21

And it occurred to me that one way we could do this without re-inventing the wheel is to use jackson. Jackson can essentially take a parse tree, either the result of parsing XML, or json, or anything (for example there's a yaml plugin), and then, there are 3 things jackson lets you do with that tree. You can either visit the nodes in the tree (they call this streaming), you can map the tree onto the datastructures built into java (essentially get a Map, or, you can map the tree onto a user defined class. The latter lets you work with a well typed class, and also lets you use jackson's annotations for controlling how the tree -> pojo mapping works (renaming fields and so on).

We could leverage all of that by creating something that goes from parquet data to the jackson parse tree, and then leave the rest of the work to jackson.

**Reporter**: [Alex Levenson](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=alexlevenson) / @isnotinvain

_{**Note**: *This issue was originally created as [PARQUET-65](https://issues.apache.org/jira/browse/PARQUET-65). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

まず、issue にリンクされている既存の POJO サポートの pull request と、Parquet からツリーへの変換に Jackson を使用する提案を確認します。Jackson ツリーとユーザー定義 POJO のマッピングを中心に統合モジュールのスコープを定義し、その後、Parquet データを Jackson 経由で利用できることを示すために必要な相互運用性テストとマッピングテストを特定します。

索引モデルが issue の本文から書いたものです。