New version of DB. Change properly entites & services, add triggers to clear USER table after deleting data form STUDENT & EMPLOYEE tables.
Add entity, DAO & service for DOCUMENT table. Actualy, not tested yet.
Finish (i hope) document service, DAO & entity.
Add transactional annotations to DocumentServiceImpl, so, now delete & update document operations are correct
Fix packages location
Merge branch 'develop'