LRDOCS-725 Javadoc

I completed the Javadoc re-add of Jorge's reverted commit. My removal commit is only removing the cherry-picked Javadoc that was generated based on the original one.

The LRDOCS-725 ticket also says to edit the AssetTag and AssetEntry service Javadoc. I was unable to find any additional Javadoc to edit (except for the class descriptions) in these classes or any Javadoc that had been removed in the logs. Let me know if there is additional Javadoc work that I missed. Thanks.

http://issues.liferay.com/browse/LRDOCS-725