Add ability to customize logging in .NET SDK

[epenet]

It would be nice to be able to have the ability to write custom logger (for example to a debug window or to a shared logger)
This implementation would allow one to write a CustomLogger, which inherits the standard Logger.

  internal class CustomLogger : Logger
  {
    internal CustomLogger() { }
    protected override void Log(LogLevel logLevel, LogStatement logStatement)
    {
      //base.Log(logLevel, logStatement);
      if (logLevel >= Level)
      {
        Debug.WriteLine(logStatement.AsString(Format, LogRequestBody, LogRequestBody));
      }
    }
  }

[epenet]

Thanks