Improved rich wrappers for BeanFactory etc

Various improvements for the rich wrappers for bean factory and friends.

- Made RichBeanFactory and RichListableBeanFactory traits instead of
  classes.
- Removed get- prefix from  Rich(Listable)BeanFactory methods so that
  they do not clash with the methods on the "plain" bean factories.
- Added RichApplicationContext
- Added apply methods to RichBeanFactory as alternative to "bean".