Show form validation errors from Django.

Author: sigurdga

fileupload/static/js/jquery.fileupload.js

@@ -805,6 +805,9 @@
             response.jqXHR = options.jqXHR = jqXHR;
             response.textStatus = options.textStatus = textStatus;
             response.errorThrown = options.errorThrown = errorThrown;
+            if ('file' in response.jqXHR.responseJSON) {
+                response.errorThrown = options.errorThrown = response.jqXHR.responseJSON.file.join(", ");
+            }
             this._trigger('fail', null, options);
         },