Enable support for a full year of 36 reacquiring weekly sessions

Hi Dan,

Teachers asked my to extend the available reacquiring weekly sessions in the form. Hope it is agreeable by you.

It now support a full year (two academic semesters) of 36 weeks.

What do you think?

add_form.php

@@ -135,7 +135,7 @@ class mod_attendance_add_form extends moodleform {
         $mform->addGroup($sdays, 'sdays', get_string('sessiondays', 'attendance'), array('     '), true);
         $mform->disabledIf('sdays', 'addmultiply', 'notchecked');
 
-        $period = array(1=>1, 2, 3, 4, 5, 6, 7, 8);
+        $period = array(1=>1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36);
         $periodgroup = array();
         $periodgroup[] =& $mform->createElement('select', 'period', '', $period, false, true);
         $periodgroup[] =& $mform->createElement('static', 'perioddesc', '', get_string('week', 'attendance'));