fixed delay in qsearch

The ajax quicksearch sent a request on every keystroke instead of
waiting for the user to stop typing.

lib/scripts/qsearch.js

@@ -14,6 +14,7 @@ var dw_qsearch = {
 
     $inObj: null,
     $outObj: null,
+    timer: null,
 
     /**
      * initialize the quick search
@@ -55,8 +56,12 @@ var dw_qsearch = {
 
         dw_qsearch.$inObj.keyup(
             function() {
+                if(dw_qsearch.timer){
+                    window.clearTimeout(dw_qsearch.timer);
+                    dw_qsearch.timer = null;
+                }
                 dw_qsearch.clear_results();
-                window.setTimeout(do_qsearch, 500);
+                dw_qsearch.timer = window.setTimeout(do_qsearch, 500);
             }
         );