TODO

- Automatically detect when a file upload has been cancelled
  and notify the client on the next progress update
- abstract out the cache so that it can work in distributed
  environments, and on platforms where Cache::FastMmap is
  not available (Windows)
- Make the cache size and location configurable
- add support to indicate which file is currently being uploaded
  when uploading multiple files at once
- Allow finer grained configuration in Apache (UploadProgress On/Off)
- clean up JS, XSL and CSS files
- add more stylesheets
- add more examples