MDL-36017 Fields numsections, hiddensections and coursedisplay are now format-specific options

- Fields added to format_legacy as default course format options;
- Upgrade script copies fields values from table course to course_format_options;
- Fields removed from table course;
- Fields removed from edit course form;
- Since front-page course has a 'numsections' setting, format_site defines it as it's option;
- Removed accessing those fields in core code unless we know that format supports them and in this
  case instead of $course = $DB->get_record('course'); we use:
  $course = course_get_format($courseorid)->get_course(); This way all format-specific options
  are added to the $course object

course/changenumsections.php

@@ -30,7 +30,7 @@ require_once($CFG->dirroot.'/course/lib.php');
 
 $courseid = required_param('courseid', PARAM_INT);
 $increase = optional_param('increase', true, PARAM_BOOL);
-$course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);
+$course = course_get_format($courseid)->get_course();
 
 $PAGE->set_url('/course/changenumsections.php', array('courseid' => $courseid));
 
@@ -39,18 +39,20 @@ require_login($course);
 require_capability('moodle/course:update', context_course::instance($course->id));
 require_sesskey();
 
-if ($increase) {
-    // Add an additional section.
-    $course->numsections++;
-} else {
-    // Remove a section.
-    $course->numsections--;
-}
+if (isset($course->numsections)) {
+    if ($increase) {
+        // Add an additional section.
+        $course->numsections++;
+    } else {
+        // Remove a section.
+        $course->numsections--;
+    }
 
-// Don't go less than 0, intentionally redirect silently (for the case of
-// double clicks).
-if ($course->numsections >= 0) {
-    $DB->update_record('course', $course);
+    // Don't go less than 0, intentionally redirect silently (for the case of
+    // double clicks).
+    if ($course->numsections >= 0) {
+        course_get_format($course)->update_course_format_options(array('numsections' => $course->numsections));
+    }
 }
 
 $url = course_get_url($course);