handling of content-type with charset included

[mpenet]

Hello,

I noticed Firefox 3+ adds charset to XHR requests when sending application/x-www-form-urlencoded requests.
Checking the rfc about it I read it is normal and can also happen with any other content-type.

see: http://www.w3.org/TR/XMLHttpRequest/

I just changed content-type checks using "=" to "contains." .

[ztellman]

A more robust fix is to use the :content-type value on the request, rather than the value in the headers. I've checked such a fix in.

[mpenet]

It makes more sense yes, thanks for the fix.