Issue #2020913 by clemens.tolboom: Fixed When attributes is not defined it will never become available for edit.

Issue #2030381 by batigolix: Fixed Call to undefined function drupal_goto() in tour_builder().module on line 195.

Issue #2021279 by clemens.tolboom: Fixed Don't allow for other then tour.tour. prefixed config items.

Issue #2020489 by clemens.tolboom: Added The overview page should if possible provide link to the page(s) the tour is about.