Adding legacy beans to CDI context: a CDI extension sample

Adding a bean which is not a CDI bean into the CDI context can easily be done through a CDI extension. However in some cases (typically when these beans are configuration aware) you need to extract their creation from the code (= configure them without updating the code. A common sample is an URL to configure.).

As a Proof Of Concept (PoC) i pushed on github cdi-light-config extension: https://github.com/rmannibucau/cdi-light-config.