merge keyDown event handling from MAIN - helps with sites such as yahoo.com

which trap all keyDown events

chrome/content/vimperator/events.js

@@ -611,6 +611,18 @@ function Events() //{{{
     }
     window.addEventListener("keypress", this.onKeyPress, true);
 
+    // this is need for sites like msn.com which focus the input field on keydown
+    this.onKeyDown = function(event)
+    {
+        if (vimperator.modes.passNextKey ^ vimperator.modes.passAllKeys || isFormElemFocused())
+            return true;
+
+        event.preventDefault();
+        event.stopPropagation();
+        return false;
+    }
+    window.addEventListener("keydown", this.onKeyDown, true);
+
     this.progressListener =
     {
         QueryInterface: function(aIID)