Thoughts?  WIP: moved 'shutdown' ns into 'app'

Posted this in chat this morning.  Does anybody have an opinion on this?  I don't really care either way, but I already did most of the work on this, so I thought it would be worth putting it up for review.

If we like this, we should ...

* combine test namespaces
* do we want to rename to 'internal' or something else?
* do something with the big comment about shutdown functionality,
  this commit leaves it out-of-place, perhaps move to README
* probably have to fix up example app(s)