CONTRIB-5091 mod_checklist Fix Postgres unknown param data type bug

Signed-off-by: Tony Butler <tonyjbutler@gmail.com>
CONTRIB-5023 prevent teachers with no group access from seeing any students in the report
Update locallib.php

Correctly center headers.
Merge pull request #22 from Syxton/patch-1
Tidy up standard entry-point boilerplate
Add Moodle 2.7 event logging support
Toggle row/column buttons added to report view - developed by Simon Bertoli