Adding unproxifier method. Closes #315 #316

I know that this class is not the most beautiful class of the world. But allow us to solve the various problems we have with weld proxies like #315 issue.

I don't like to have hard coded weld class. But at this time only Weld implements the CDI 1.1 spec. So this is not a problem right now

This change can solve problems I have migrating exception handler to use invoke binder: https://github.com/caelum/vraptor4/tree/ot-mirrorless