Tools dropdown empty for anonymous users in the issue navigator

The tools dropdown on the issuenavigator on JAC is empty for logged out users. There's actually no actions to be displayed to logged out users, so the whole 'Tools' dropdown should be hidden.

Currently header.jsp (for the issuenavigator) is implemented quite badly. It has a lot of 'if' statements in the JSP to determine what dropdown items to show. This makes it hard to hide the whole dropdown if there's no items, and to determine the last time (to apply class="last").

I think this should be changed such that the web-action returns a List of items/groups and all the relevant checks for the times are done in the web-action. Then in the JSP we simply iterate over the items (if there's none, we hide the whole dropdown) and apply class="last" to the last item.