Specify which extensions are used for JavaScript source code parsing

For projects that make use of JavaScript extensively there is need to tell qdoc which files can be treated as JavaScript.

What is being sought is to have line the following in the .qdocconf file
javascript.sources.fileextensions = "*.qtx *.qtt"

At the moment there is need to provide a new CodeParser/PureQDoc subclass for handing of JavaScript sources outside of .qml file.