various adjustments to improve code

1. Wrap the code in a IIFE, passing `jQuery` into the function via the `$` param to allow use of the dollar sign alias in all cases.
2. Removed call to `ready` in favor of shorter alias function.
3. Remove dependence on specific CSS classes used by Fine Uploader.  Used an API method that returns the container element for a specific file instead.
4. Made use of `getKey` to create the public URL for the stored object.