This PR was merged into the 2.0.x-dev branch.

Discussion
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Remove mandatory dependency on request_stack and some monolog improvements

This lets everything work with Silex which lacks a request_stack, and I also made a couple changes to the monolog bootstrapping so it's easier to just override the monolog.handler OR monolog.handlers, before you kinda had to redefine both to customize anything.

I also moved the monolog.handler.debug out of the GroupHandler which makes more sense I think because if it is in the group then it falls under the not_found_activation_strategy and therefore even in debug mode you won't get any logs unless you get an error-level record.

Commits
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50fbc38f Remove mandatory dependency on request_stack and some monolog improvements