Allow injecting multiple components via Iterable<S>

Often a constructor in a component will only copy the collection of objects from the parameter into a collection in the field (commonly using Guava's ImmutableList.copyOf()).

IDEA tends to recommend changing this sort of thing to Iterable, but if I change it to Iterable, PicoContainer says that it doesn't know how to inject that. To meet it half way, I inject it as Collection, but it would be nice if Iterable would work as well.