Test suite improvements

1. allow to replace services in DIC (for testing)
2. allow to create instances of Application class (for testing)
3. fixing typehint on DIC in Application
4. detaching BrowserConfiguration from BrowserTestCase after test is finished
5. removing pre-event-dispatcher commented-out code
6. minor path change for code coverage collection (for testing)
7. adding tests for Application, DIContainer,
8. create base test case class event dispatcher-based classes testing