Adjust diff HTML output for parsing

[mc-17]

It would really tickle my pickle if the diff output had either id values on elements or a hierarchy of tags so that it became easier to parse. For example, to get updated dylibs you must currently find the DSC h2, then the updated dylibs h3, then find any ul below it.

If they had some predictable id attribute, such as [dsc|fs]-updated or putting them under a div with the same name, parsing it would be much simpler.