ids are represented by simple strings, and are created inconsistently throughout the standard doclet, including in SectionName, Links, and with miscellaneous string constants.

It would be good to introduce a type-safe wrapper class, HtmlId, and then centralize the management of ids in a new factory class, HtmlIds.

As a followup up, it would then be good to review the names of the ids we generate, to attempt a more consistent naming scheme.