Merge branch 'http-header-case-insensitive' of https://github.com/TheDistantSea/form into TheDistantSea-http-header-case-insensitive

Author: malsup

jquery.form.js

@@ -635,7 +635,7 @@ $.fn.ajaxSubmit = function(options) {
                     s.dataType = 'xml';
                 xhr.getResponseHeader = function(header){
                     var headers = {'content-type': s.dataType};
-                    return headers[header];
+                    return headers[header.toLowerCase()];
                 };
                 // support for XHR 'status' & 'statusText' emulation :
                 if (docRoot) {