Rename MetaDatumDepartments to MetaDatumInstitutionalGroups

Squashed commit of the following:

commit 3e13bda8fe79661f699a35c53e8b335dcf88777b
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Tue Sep 23 08:30:12 2014 +0200
Update Schema diagram after renaming to MetaDatumInstitutionalGroups