Please don't merge it to Master. I am a newbie.
I changed some numbers in the file (filebrowser\frontend\src\css\styles.css) to make the preview window much larger. It looks pretty good. All the buttons and bars are trandsparent and shown above the pics layer. Every thing works great, expect some buttons are not in the correct position, especially in the PC's browser. I don't know how to fix it. And maybe I changed some unnecessary numbers. So, please don't merge it to Master. Just compile it and take a look. I hope some one can improve it.
By the way, after the change, the pics' direction is correct in the phone's web browser. Before, the phone's web browser always showed some pics in wrong direction.
