New Media Manager for Joomla! CMS

Hi All,
Let me introduce the new media manager for Joomla! along with this PR. With this project I have introduced 12 new things to Media Manager. I have constructed a document describing this project in detail.
The link for the document is : https://docs.google.com/document/d/1mZMwBU_hW7AshL5rkAdIyswQmzBmP1L8L1PdM093rB0/edit?usp=sharing

This new Media Manager add entries to your database. Therefore I kindly request you to go through "Testing Instructions" at document before testing this.


Thank You!

![pic1](https://cloud.githubusercontent.com/assets/1543384/3423841/afe25922-ffad-11e3-9a9b-334c77e841a8.JPG)