Change from using depenecny injection array to variables

Hi

Dependency injection is great, but there are things in the bolt code I find hard. Its hard working in an IDE as there is no code completion and so on. For example  $this->app-['session']->setFlash('error', $error); works great but setFlash is deprecated but there is no way to tell that in the ide. Instead I have refactored the code to be  $this->app->session->setFlash('error', $error); so the IDE knows session is \Symfony\Component\HttpFoundation\Session\Session

All this does is use the doc block property and some magic methods in the bolt Application.php file

I have also changed references for Silix\Application to Bolt\Application because that is what you are passing around.

If you use an IDE like phpstorm or netbeans I think this would make some of the code easier, if not then I do not think you will see much is any of an advantage

Take a look, maybe put it in a test branch

Thanks