POD tweaks
t/; test tweaks
Allow passing in circular dep callback

Not sure I like this design. I think I'd rather call out to a method that
die()s by default, and pass the current $state to that method.
Classes can override to do scarier stuff.

	modified:   lib/MooX/Role/DependsOn.pm
tests / POD for circular dep callbacks

	modified:   lib/MooX/Role/DependsOn.pm
	modified:   t/depends.t
Merge branch 'circular-cb'

* circular-cb:
  tests / POD for circular dep callbacks
  Allow passing in circular dep callback