LPS-47692 convert DocumentLibraryUpload to a plugin

Hello @natecavanaugh,

Here is an update for <strong>LPS-47692 -  convert DocumentLibraryUpload to a plugin </strong>. 

Please let me know if you have any questions. ^_^

note: https://github.com/marclundgren/liferay-portal/pull/141#issuecomment-51414589