Don't register factories imported from other bundles
Don't register factories imported from other bundles

If a bundle imports a factory class from another bundle (e.g. from foo import BarFactory), do not try to register it automatically.

If a developer wants to register this factory, he will have to do so in the bundle activator.

Fixes #53

ahmadshahwan/ipopo,tcalmant/ipopo,ahmadshahwan/ipopo