add contact_form link in top navigation

- add contact_form URLs to gnuviechadmin.urls
- set href of contact link to 'contact_form'

gnuviechadmin/gnuviechadmin/urls.py

@@ -17,6 +17,7 @@ urlpatterns = patterns(
     url(r'^mail/', include('managemails.urls')),
     url(r'^osuser/', include('osusers.urls')),
     url(r'^admin/', include(admin.site.urls)),
+    url(r'^contact/', include('contact_form.urls')),
 )
 urlpatterns += patterns(
     'django.contrib.flatpages.views',