MDL-8807 and MDL-8564: Jamie had replaced the three group modes with …

…Yes and No, for some

undocumented reason (See http://moodle.cvs.sourceforge.net/moodle/moodle/lib/form/modgroupmode.php?diff_format=h&view=log&pathrev=MOODLE_18_STABLE#revtext).
I reverted his changes, and this seems to work normally now.

lib/form/modgroupmode.php

@@ -42,8 +42,11 @@ function onQuickFormEvent($event, $arg, &$caller)
         switch ($event) {
             case 'createElement':
                 $choices = array();
-                $choices[0] = get_string('no');
-                $choices[1] = get_string('yes');
+
+                $choices[NOGROUPS] = get_string('groupsnone');
+                $choices[SEPARATEGROUPS] = get_string('groupsseparate');
+                $choices[VISIBLEGROUPS] = get_string('groupsvisible');
+
                 $this->setHelpButton(array('groupmode', get_string('groupmode')));
                 $this->load($choices);
                 break;
@@ -52,4 +55,4 @@ function onQuickFormEvent($event, $arg, &$caller)
     }
 
 }
-?>
+?>