[FR] Add support for toolbar

[farfromrefug]

Would be nice to have support for the toolbar ;)

Great job!

[PatrickNLT]

Hi, could you be more specific? The toolbar itself can be manually added to any view controller, including if you're using it with ADTransitionController or not.

[farfromrefug]

You should have the toolbar as a property of the navigationcontroller to have the same api as with the UINavigationController which has a toolbar property.
I already started to integrate it in my branch.
If i finish it and test it far enough, i will create a PR