Adding support for @PostConstruct, @PreDestroy and @Resource to Guice

I do like guice as a Dependency Injection engine; I think it has a lot of promise; particularly if 2.0 is released soon :)

I still struggle sometimes, coming from a spring framework mindset, figuring out how to do some stuff. Though I love the @Provides support in trunk of Guice. Here's hoping 2.0 is out soon! :)

I've experimented recently adding support for ConstructorInterceptors into guice so you can add custom lifecycles like @PostContruct from JSR250/EJB3 or Spring's InitializingBean etc. 

I've also created a patch to support closing of singletons such as via @PreDestroy or spring's DisposableBean.

Slightly more wacky is a patch adding support for custom injection point annotations which allows you to easily support things like 

• @Resource from JSR 250/EJB3
• @PersistenceContext from JPA
  
• the various JAX-RS annotations like @Context, @PathParam etc
• WebBeans @In
• Spring's @Autowire
• Apache Camel's injection annotations like @EndpointInject or @Produce

Feedback greatly appreciated!