ClassSchema must reset identity property and identifier property when being made value object
If a class schema exists, and the type is set to value object, properties only useful for entities must be reset.
[+FEATURE] FLOW3 (Property): The PropertyMapper now only maps to settable properties and no longer relies on the class schema to determine the type for the target property - it uses the setter parameter's type if available and falls back to the class schema if needed. Resolves #5612.
[+FEATURE] FLOW3 (Reflection): When reflecting classes entities and value objects are checked for being declared prototype, resolves #6141.
[+FEATURE] FLOW3 (Reflection): ClassSchema now enforces consistency when it comes to value objects and identity/identifier properties, resolves #6140, resolves #6142.
[+BUGFIX] FLOW3 (Persistence): Fixed left over JCR constant in AbstractSqlBackend, fixes #6153.