Extensability improvement in createTextFlowFromXML

Hey TLF team,

In TextLayoutImport.createTextFlowFromXML, there is a second argument 'textFlow' which is only ever called from BaseTextLayoutImporter with a value of null.

I guess the point of this is to allow a subclass of TextFlow to be passed in as an alternative to having createTextFlowFromXML create a TextFlow on its own (e.g. var element:FlowElement = super.createTextFlowFromXML(xmlToParse, new MySubClassedTextFlow()); )

but if this is that case then the first line needs to be changed from:

var newFlow:TextFlow = null;

to

var newFlow:TextFlow = textFlow;

This would allow custom importers to subclass TextFlow, but still be able to use the TLF importer framework.

Do you agree, and if so can this change be made on the trunk?