Add logging customization

[brunorro]

A "logging" parameter was added to the server confinguration class to customize named logging options. In case the parameter is empty, defaults are applied.

Thank you!

[radupantiru]

This is very helpful. Any word if this is going to be reviewed?

[brunorro]

Go on, it's always a pleasure finding that something I wrote can be helpful for someone else!
I hope it can be easily reviewed, though :)

[askeklok]

This would be very useful, will it be merged?