Update format.php

Update format.php to work with Moodle2.4
Merge pull request #13 from gjb2048/MOODLE_23_STABLE

Fixes
Merge pull request #12 from roelmann/MOODLE_23_STABLE

Moodle 23 stable Update format.php for Moodle2.4
Merge pull request #14 from gjb2048/MOODLE_23_STABLE

V2.3.2.1
V2.3.2.2
V2.3.2.2