Clean up Feedback modules coding style

These changes consist primarily of whitespace fixes and as such only a very little bit of code has changed. Test that you can still add/edit/delete feedback modules as an admin or teacher Test that as a student you can submit feedback Test the reporting as an admin/teacher Testing the issue with new function xxx_param_array() turn debug on for developer create a feedback and an item multichoice "Multiple choice - multiple answers" (checkbox) with two or more options go to complete this feedback and check one or more checkboxes while submitting no error should be raised The special changes are done in feedback/lib.php in functions feedback_check_values, feedback_create_values, feedback_update_values and in feedback/item/multichoice/lib.php in function item_array_to_string.