lib::Depend<TY> works as drop-in replacement for lib::Singleton<TY>
This changeset removes the convoluted special cases like
SingletonSub and MockInjector.
the rules-based configuration and query system
will be located within the core application,
while the concrete implementation facilities
are expected to reside within the session or
maybe also the GUI.
This is kind of a 'rochade' refactoring to resolve
circular library dependencies and confine the parts
dependant on the session and MObjects to the Proc-Layer
And while we're in the middle of chainsaw surgery,
we'll concentrate further query-based facilities
alongside the config-rules within the App core.
