Allow div around `dt` and `dd`s

[marcoscaceres]

HTML now allows:

<dl>
   <div>
    <dt>term<dt>
    <dd>def</dd>
   </div>
</dl>

Relevant spec change:
whatwg/html@5454d70

[geoffmcl]

@marcoscaceres, thanks for your issue transfer...

And on the sample given, current libtidy does go into freefall...

This seems part of the ongoing effort to bump libtidy parsing
into this century ;=)), so the FR label...

As @sideshowbarker merge sort of points out, we all
need to change with the times... it would be even greater if
one change mirrored others... he is a htacg dev, like you...

Look forward to some code suggestions to fix this... thanks...

[geoffmcl]

As we are about to release 5.4, moving this to next 5.5.

Have added a sample in_468-2.html which passes validation! Tidy should do likewise...

As usual comments, patches or PR very welcome... thanks...

[balthisar]

Four and half years later, finally fixed.

[marcoscaceres]

Awesome! thanks for keeping the project going.