Working on changing "author" to "group".
Done but not tested.  Any existing SQL database
should be modified using:
    ALTER TABLE session CHANGE COLUMN `author` `group`  varchar(30) DEFAULT NULL;
Found Bug #2418, removed some old files.
After two bug fixes, it seems to work
in both student mode and author mode.
Merge branch 'bvds'
Merge branch 'master' of https://github.com/bvds/LaitsV3