Pause the receiving of data

[AlBura]

It's more a new feature request, I'd like to allow the user to stop the stream of data (e.g. the user already find the line was looking for) .
The change could be in NlogViewer.xaml.cs

`
private bool _isPausing = false;
[Description("Pause the receiving of data"), Category("Data")]
[TypeConverter(typeof(BooleanConverter))]
public bool Pause
{
get { return _isPausing; }
set { _isPausing = value; }
}

`

and in method LogReceived the _isPausing can be checked.

If you'd like I can push a branch with the changes.