[JENKINS-19456] Publish artifacts as documents.

Also see [JENKINS-19456] (https://issues.jenkins-ci.org/browse/JENKINS-19456).

This feature provides a feature to publish artifacts as documents.
* You can refer contents of a document of each build on Web browsers.
* You can refer contents of a document of the latest build of a project.

These are screen shots:
* Configuration page. You run "Archive the Artifacts", then run "Publisn Artifacts as Documents".
    ![configuration](https://f.cloud.github.com/assets/3115961/1102654/e64f920c-1842-11e3-8857-5b95c47c68be.png)
* Links to documents are in the job page.
    ![links](https://f.cloud.github.com/assets/3115961/1102655/1dfecc7c-1843-11e3-8a7b-782dd86edf4a.png)
* You can view contents of documents in your browser.
    ![onbrowser](https://f.cloud.github.com/assets/3115961/1102656/31cf6ab8-1843-11e3-9590-55335c585d09.png)