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
This MUST be selected depending on whether logging is enabled; as soon as this function is entered the opportunity for the compiler to eliminate dead code decreases.

```d
version (loggingAtLogLevelEnabled)
{
    ref Logger log(...)(...) { ... }
}
else
{
    ref Logger log(...)(...) { return defaultLogger; }
}
```