added class for borderless fieldset

less/qfq-bs.css.less

@@ -1283,6 +1283,14 @@ legend {
   border-radius: 0 0 4px 4px;
 }
 
+.qfq-fieldset-borderless {
+  border: none;
+}
+
+.qfq-fieldset-borderless legend {
+  border: none;
+}
+
 /* glyphicon functions */
 .icon-flipped {
   transform: scaleX(-1);