[Ur] New library: AJAX-style file upload

[Adam Chlipala]

This new library may be of interest:
     http://hg.impredicative.com/ajaxUpload

It implements an AJAX-style file upload widget.  That is, one can upload 
files to a temporary area on the server without refreshing a page, and a 
client-side callback is called with an abstract handle to the file that 
was uploaded.

This library also gives a very basic example of both the C and 
JavaScript FFIs.