Updated to support Bootstrap3.
Fixed navigation menu for IE < 8.
Use a separate demo stylesheet to fix styles for IE<9.
Added link to jQuery UI.
Updated icon info (Glyphicons => Font Awesome).
Ensure compatibility to Bootstrap 3 by applying the animated progress bar background to .progress-bar elements.
Ensure compatibility to both Bootstrap 2 and 3 by selecting the progress bar child element without class name.
Support passing a list of files to the delete method. Closes #2505

The format follows the upload file name parameter scheme:
DELETE /server/php?files[]=cat.jpg&files[]=dog.jpg