New media manager

- Make media manager has similar template to other components.
- Add filter like category/access filter, search box and ordering filter.
- Add categories to manage ACL at category level.
- Add check in/ check out function to avoid conflicts.
- Add sync database button to sync database information with real folders.
- Treat media as asset to manage ACL at item level.
- Copy ucm_content structure for easy adaptation of ucm later.
- Add auto thumbnail generation with configuration on global configuration: choose width of thumbnail or ratio between thumbnail and image.
- Add information view which is similar to article view of com_content in which administrators can change media information, publishing information and media permissions.
- Add editor view in which users can edit image(rotate, flip, resize, crop, duplicate)
- Decrease the dependence on Mootools. All of new javascript are in Jquery. Traslate some old mootools to Jquery as well.
- Totally new MVC and database-driven now.