fix firefox button styling

src/static/css/pad.css

@@ -749,6 +749,11 @@ table#otheruserstable {
   color: #666;
 }
 
+.buttonicon::-moz-focus-inner {
+  padding: 0;
+  border: 0
+}
+
 .buttonicon:focus{
   border: 1px solid #fff;
 }