Fixed issue with NET MVC 4 multipart uploads

.NET's MVC 4 fails to parse multipart uploads which lack a trailing CRLF. This is safe to add to all multipart requests since it is after the final boundary which is considered part of the epilogue and is ignored (per RFC1341 section 7.2.1).
I think this trailing "\r\n" could just be added to the stream created on line 105.