Remove traits if possible, simplify stack trace

[codeguy]

Will require more investigation.

[geggleto]

I floated the idea of removing Callable Resolver to it's own repo. Ideally it can be provided as a static or singleton class inside the DIC. There really isnt a reason for it being a trait.

Moving it to it's own class should stop some of the jumping across the files.

[codeguy]

@geggleto I wasn't paying much attention to Slim when this was added, so I'm not 100% familiar with the internals of the current implementation. Can you walk me through it sometime soon on Slack?

[geggleto]

@codeguy Yeah, just ping me when you want to go through it.

[akrabat]

Maybe the trait should become a class and be composed into App and Route?

[mathmarques]

I think that a class MiddlewareAware composed into App and Route would be better than extends an abstract class.
If you want, I can make this change.

[akrabat]

If you want, I can make this change.

Yes. This probably affects into the PSR-15 support that @bnf has started.

[l0gicgate]

Closed as per #2555