Exposed filters don't work on embedded views without overriding the path

If you add an exposed filter to any of the views embedded by signup (the user list now, and the admin list as soon as #352328: Replace (optionally?) node/N/signups/admin with a views bulk operations view? lands), the filter is completely broken since the view doesn't know its own path. Luckily, merlinofchaos already thought of this, and if you specify $view->override_path = 'some path' on the view object before you embed it, it should all Just Work(tm).