Object Versioning: enabled + simplified prototype versions tests
Object Versioning: set constructor function in construct-trap
Object Versioning: __objectID and __protoID not-enumerable

proxied objects have two special properties that both shouldn't show
when enumerating properties or retrieving all keys from an object.

-- configuration --

__objectID: not writable, not configurable, not enumerable
__protoID: writable, not configurable, not enumerable
Object Versioning: slight refactoring of test case
Object Versioning: tiny refactoring, renamed method