Trace messages with Trace and Debug levels are emitted without trace event type

[ATECoder]

... as a result, these messages cannot be filtered. I suggest changing this:

`

    public void Emit(LogEvent logEvent)
    {
        if (logEvent == null) throw new ArgumentNullException(nameof(logEvent));
        var sr = new StringWriter();
        _textFormatter.Format(logEvent, sr);

        var text = sr.ToString().Trim();

        if (logEvent.Level == LogEventLevel.Error || logEvent.Level == LogEventLevel.Fatal)
            Trace.TraceError(text);
        else if (logEvent.Level == LogEventLevel.Warning)
            Trace.TraceWarning(text);
        else if (logEvent.Level == LogEventLevel.Information)
            Trace.TraceInformation(text);
        else
            Trace.WriteLine(text);
    }

`
to this:

`

    public void Emit(LogEvent logEvent)
    {
        if (logEvent == null) throw new ArgumentNullException(nameof(logEvent));
        var sr = new StringWriter();
        _textFormatter.Format(logEvent, sr);

        var text = sr.ToString().Trim();

        if (logEvent.Level == LogEventLevel.Error || logEvent.Level == LogEventLevel.Fatal)
            Trace.TraceError(text);
        else if (logEvent.Level == LogEventLevel.Warning)
            Trace.TraceWarning(text);
        else
            Trace.TraceInformation(text);
    }

`

A better granularity could be had if Trace had exposed the TraceEvent method, of the TraceInternal class.