MDL-31830 course: several small code improvements
* I can rebase this for you/the integrator before it goes in for sure no probs
* Fixed double phpdoc block of course_change_visibility
* Moved permission checks out of course_move_after_course and into helper function.
* Reviewed setType calls for editcategory_form.php.
* Reviewed all uses of can_resort and added more specific methods.
* Fixed method mentioned in exception for resort methods.
* Converted calls to fetch courses to call get_course.
* Exceptions now thrown when trying to move courses and problems arise.
* Fixed unnecessary namespace hinting in core_course_management_renderer.
* Abstracted common logic of can_resort_any and can_change_parent_any.
* Removed check for system level capability from has_manage_capability_on_any.
* Reviewed debugging calls I've introduced.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=67e1f26874cf11af8ef6d6da50e66f27504bfa01
http://github.com/moodle/moodle/commit/67e1f26874cf11af8ef6d6da50e66f27504bfa01
+ 2.6 en [cannotmovecourses,core_error]