Merge branch 'f-version-history' into 'dev'

CHANGELOG.md

conf/core/cache.ccf

conf/core/server.conf

...n/java/org/caosdb/server/database/BackendTransaction.java

src/main/java/org/caosdb/server/database/DatabaseUtils.java

...backend/implementation/MySQL/MySQLInsertSparseEntity.java

...implementation/MySQL/MySQLRetrieveTransactionHistory.java

...end/implementation/MySQL/MySQLRetrieveVersionHistory.java

...backend/implementation/MySQL/MySQLUpdateSparseEntity.java

...se/backend/interfaces/RetrieveTransactionHistoryImpl.java

...rver/database/backend/transaction/InsertSparseEntity.java

...abase/backend/transaction/RetrieveTransactionHistory.java

.../database/backend/transaction/RetrieveVersionHistory.java

...ver/database/backend/transaction/RetrieveVersionInfo.java

...sdb/server/database/backend/transaction/UpdateEntity.java

...rver/database/backend/transaction/UpdateSparseEntity.java

...rver/database/backend/transaction/VersionTransaction.java

...sdb/server/database/proto/ProtoTransactionLogMessage.java

...n/java/org/caosdb/server/database/proto/SparseEntity.java

.../org/caosdb/server/database/proto/VersionHistoryItem.java