Fix #190 regression: No new tab for "javascript:".

The last patch accidentally made pseudo-links
(palette colors and emoticon shortcuts, which
have javascript:void('...') labels) create an
empty tab on clicking. They should be exempt.

js/core/visual.js

@@ -315,7 +315,7 @@ visual = {
    * Make links open in a new tab.
    */
   linkOnClick: function(jq) {
-    $('a[href]:not([href^=#])', jq).click(function(event) {
+    $('a[href]:not([href^=#]):not([href^=javascript\\:])', jq).click(function(event) {
       event.preventDefault();
       window.open(this.href);
     });