Support DL/DIV

[ndw]

TIL: for at least five years, it has been the case that HTML allows the dt/dd children of dl to be wrapped in a div:

<dl>
  <div>
    <dt>First</dt>
    <dt>Premier</dt>
    <dd>Some random stuff</dd>
  </div>
</dl>

1. The stylesheets should do this. It simplifies CSS styling.
2. The stylesheets should have an option to output each of the terms in a varlistentry as separate dt elements.