Bug 1072757 - Implement SettingsCore

We will deprecate SUB_MODULE_PARENT if everyone is using System.register()
There should be nobody other than System module being attatched under window.

The reason of existence of PARENT is because NOT everyone is using System.register/System.request to communicate the module which is not its submodule or parentmodule now.

BTW, namespace doesn't convince me because as a very deep leaf node I don't want to remember who is my grandpa. Why?