Database data model documentation update
Cont'd writing SQL tests, not so easy; still non-deterministic issues with multichunks
Add tests for ApplicationSqlDao
Add tests for ChunkSqlDao
Fixing bug that made ThreeClientsOneLoserScenarioTest fail
Started implementation of tests for DatabaseVersionSqlDao
Cont'd SQL tests: MultiChunkSqlDao, still not working properly
Cont'd SQL backend: MultiChunkSqlDao and FileContentSqlDao tests rework; DatabaseVersionSqlDao tests cont'd