#985 Don't disable existing loggers by default

[janoskut]

Rationale:
In behave, loggers are usually initialized before "before_all()" and "setup_logging()" are invoked.
When using a file config, the default behavior of the logging module is to disable existing loggers (see warning in https://docs.python.org/3/howto/logging.html#configuring-logging).
Changing the default behavior to not disabling the existing loggers matches behaves logger users better.
By passing the **kwargs into "fileConfig()", we still allow all desired behaviors.

[jenisys]

Correction of description above:

• behave does not initialize the logging subsystem before calling the before_all() hook. If this is the case, it will be corrected.
• BUT: The user code that is imported via „environment.py“ may pre-initialize the logging subsystem.
• The logging module/subsystem uses the init-once only strategy which causes must of the problems or misunderstandings when using it.

[janoskut]

@jenisys this actually exactly what I meant. Does it make it clearer if I change the first sentence to:

In behave, loggers are usually initialized by user code before "before_all()" and "setup_logging()" are invoked.

More rationale in #985.

[jenisys]

No (no change needed from my side), I just wanted to clarify the point that it can be understood by others when reading the ticket.

[janoskut]

@jenisys is there something I can do to push this change further, like help to clarify any doubts, or add more tests?

[jenisys]

I am working on it.