OWB-897 defining interceptors even for custom InjectionTargets - note: if someone has some more time it would be great to split InjectionTargetImpl in 3 implementations (the previous one, a DelegatingInjectionTarget and a SimpleInjectionTarget which doesn't hold any proxy info)

git-svn-id: https://svn.apache.org/repos/asf/openwebbeans/trunk@1520857 13f79535-47bb-0310-9956-ffa450edef68