the wiki menu item got removed from the main menu when wiki_menu_items was developed
forcing attributes to be set is done differently since rails 3.2+: assign_attributes({ … }, :without_protection => true)
the default sort order in the gem version of awesome_nested_set is called :order_column. also fix a test that didn't expect the children to be sorted by name, now it does...
fix a test that i broke a couple of commits ago
in order to have these tests to always pass, we need to make sure the database is clean before each test run (this actually should be done for every test, but hey…)