Implement lists in RTF reader

[walling]

It could be nice if the RTF reader was able to parse \listtable and read \levelnfc (type of list) and possibly \levelstartat (list start value) as documented here. It should also implement list overrides, but just to get the proper reference for \ls elements.

I have a lot of tiny RTF documents, some including bulleted/numbered lists, and I would love to be able to preserve this information and output it as XHMTL.

[brendonh]

I agree that would be nice and I'd be super happy if I got a pull request for it ;-)