minor refactor of configuration validation and fixing some tests
finished implementation of install concrete beans (inScope and asRegistrationType)
All InstallBeanTest tests are green!
some code cleanup only
refactoring of (test) code
preparing provider tests
basic provider feature is working
enhancing some provider functionality
preparing provider dependency injection via tests
resolving provider himself (instead just of providee type) now works as well
provider now supports dependency (except of depending on another provider)
minor enhancements for provider feature