Made uploading work in IE. Made uploading work if filename contains URL characters.

IE didn't like overriding mimetype on the JavaScript side, and some versions didn't like the onchange attribute on the input. In any case, I think it's a better practice to attach event handlers in the JavaScript.

Quoting the object name is a safe change, I think, and it allows uploading of files like "this&that.jpg".

The space between the percentage and the message is just to make it easier to read.

I can certainly split these changes out if you prefer.