new utility module: File MIME type

I got frustrated with files uploaded via the Upload module being assigned seemingly random MIME types, depending on the client that originally uploaded the file. So I made a little utility module -- http://drupal.org/project/filemime -- that may be useful for anyone using the Upload module. It rewrites the MIME type for each file upload based on a server-side mime.types file and/or custom settings.

It hasn't been heavily tested yet so please file an issue if you find any..