Update css and how the input is wrapped and how js is attached to make the file upload work in IE.

IE8 & 9 do not allow programatic clicks to add a file and trigger an upload. So in order for the upload button to both have a custom styled button and to work in IE8 & 9 we have to position the input button above our custom button and make it transparent.
Add authenticity token to fileuploader
IE updates (refactor to work the same in all newer browsers).