Text()

More DOM classes started i.e. DocumentType, TextNode change to Text etc few others stubbed out.

As domonic started as a tag builder faking a few dom methods, it is now evolved a lot more than that as I integrate things like d3 and expatBuilder it has to perform more like a regular DOM so have been plumbing in more parts.

Attr upgraded a bit and method around namepaces etc.

The create_element methods on dom and html now check first if there is an existing tag. not sure how to access module methods so doing it via a globals lookup on that module which seems to work i think.

ParseString is started but you probably shouldn't use unless for really strict xml type documents. But it may be better than my parser for basic stuff and is helping drive the DOM so is there to tinker with.

Likely to be lots of bugs on new features as its a very stubby commit. As always don't trust undocumented features.

Assertions added to make it a bit more reliable to change things and to quieten the tests a bit.