Hookable.define is support to property descriptor(get),now.
Observable.define's descriptor argument is include equals option,now. equals option define condition of property change.
Refactoring. Create internal function provideMethodsFactory and remove duplicated code.
Refactoring. Add the namespace for internal function.
Refactoring. Extract InternalObject.PropertySpecific.
Refactoring. Extract InternalObject.PrototypeWalker.
Refactoring. Extract BeautifulProperties.Equals.