WIP: String IDs

src/main/java/org/caosdb/server/CaosDBServer.java

src/main/java/org/caosdb/server/caching/JCSCacheHelper.java

...ava/org/caosdb/server/database/access/AbstractAccess.java

src/main/java/org/caosdb/server/database/access/Access.java

...ckend/implementation/MySQL/MySQLGetDependentEntities.java

...tabase/backend/implementation/MySQL/MySQLGetIDByName.java

...end/implementation/MySQL/MySQLGetUpdateableChecksums.java

...end/implementation/MySQL/MySQLInsertEntityProperties.java

...database/backend/implementation/MySQL/MySQLListUsers.java

...tabase/backend/implementation/MySQL/MySQLRetrieveAll.java

...ckend/implementation/MySQL/MySQLRetrieveCurrentMaxId.java

...backend/implementation/MySQL/MySQLRetrieveProperties.java

...abase/backend/implementation/MySQL/MySQLRetrieveUser.java

...atabase/backend/implementation/MySQL/MySQLUpdateUser.java

...main/java/org/caosdb/server/database/proto/ProtoUser.java

src/main/java/org/caosdb/server/datatype/ReferenceValue.java

src/main/java/org/caosdb/server/entity/Entity.java

src/main/java/org/caosdb/server/entity/EntityID.java

src/main/java/org/caosdb/server/entity/EntityIdRegistry.java

...va/org/caosdb/server/entity/EntityIdRegistryStrategy.java