Use the sourceLevels parameter to the TraceSource constructor to initialize the trace source

Consider the following test program:

    using System;
    using System.Diagnostics;

    public class Foo
    {
	public static void Main()
	{
		var t = new TraceSource("Test", SourceLevels.All);
		Console.WriteLine(t.Switch.Level.ToString());
	}
    }

If you run this using Microsoft.NET, it prints "All".  If you run it with mono, mono prints "Off".