Defer introduction of PublicMembers utility class for the moment.

This reverts commit 9bb09dc35480c62ae62219cab08fb3f9f5aee32d.
Stop member iteration at j.l.Object base
Move atInject check to BeanListener so BeanProperties can be re-used for non-injected instances whose types might still happen to have atInject annotated members
Treat adders like setters (helps with re-use inside plexus configurators)