Deleting the floating banner could result in the page spacer being left

behind. We now override remove() and get rid of the spacer as part of

the DOM removal process.

Had a reply banner on the page. Scrolled down so it was floating.

Deleted the last comment to make the banner go away. Previously, there

would still be a spacer there, and any new banner would appear after.

After this fix, that spacer was gone.