std.logger

String logging facilities for Phobos.

Docu:
http://burner.github.io/phobos/phobos-prerelease/std_logger_core.html
http://burner.github.io/phobos/phobos-prerelease/std_logger_stdiologger.html
http://burner.github.io/phobos/phobos-prerelease/std_logger_filelogger.html
http://burner.github.io/phobos/phobos-prerelease/std_logger_multilogger.html
http://burner.github.io/phobos/phobos-prerelease/std_logger_nulllogger.html
http://burner.github.io/phobos/phobos-prerelease/std_logger_templatelogger.html

dub
http://code.dlang.org/packages/logger
I thought of something. you can now disable LogLevel at compile time with version statements.
That replaces functions like trace(lazy...) with version that don't have the lazy on them. This way the performance will be good right now and we can change it once the compiler can get rid of lazy function without statements.