MDL-31830 course: management interface fixes as noted

* Fixed the highlighing of the default category when no categories have been selected.
* Fixed the bug preventing the action menu for AJAX loaded categories from functioning.
* Repositioned course idnumber infront of course actions.
* Fixed display of moveup on first item and movedown on last item (courses and categories)
* Fixed up resort selected categories string.
MDL-31830 course: fixed interface issues with limited user

* Navigation/settings now show best available option.
* Resorting categories works now for limited access user.
* Display of up and down arrows corrected.
* Checkboxes no longer displayed if an action can't be performed.