1st) event with the new `__init__` method and the early Acquisition wrapping, self was always without an Acquisition context in here. No idea why. I even suspected the `@property` decorator for removing the Acqusition context, but i didn't verified this weird idea.

2nd) getSiteManager without a site context always returned the current site. this also prevented a nested sub-subsite registry proxy, which passes queries up to the root registry.