Refactored the tools menu and added method for apps to register tools themselves

apps/navigation/templates/generic_link_instance.html

@@ -0,0 +1 @@
+<a class="{{ link.class }}" href="{{ link.url }}">{% if link.famfam %}<span class="famfam active famfam-{{ link.famfam|default:'link' }}"></span>{% endif %}{{ link.text|capfirst }}{% if link.error %} - {{ link.error }}{% endif %}{% if link.active %}<span class="famfam active famfam-resultset_previous"></span>{% endif %}</a>{% if horizontal %}{% if not forloop.last %} | {% endif %}{% endif %}