Refactored play.api.Logger

 - Changed #map to #foreach. Should use #foreach instead of #map for side-effects.
 - Put some line breaks.
 - Fixed scaladoc comment
 - Removed unnecessary imports
Removed a parameter that has no format specifier.
Merge pull request #1331 from tototoshi/refactoring-logger-config

Refactored play.api.Logger
Merge pull request #1334 from tototoshi/patch-2

Removed a parameter that has no format specifier.