Better implementation(s) of DefaultLifecycleManager

The current impl of DefaultLifecycleManger is flawed. The one registered against the root container will affect all child containers regardless of whether they may have been instantiated with their own impl of LifecycleManager. This is because the visitor impementation is a bit overzealous.

Aslak and I have talked of fixing this. I changed it locally and let Aslak look at the changes. He's mulled it and proposed an alternate fix to the problem. That was about eight weeks ago, and we both sit not applying our loal changes.

This issue should give us a chance to upload our patches for some debate on the way ahead.