NG Music Artwork de xeaf

This extension adds a very little detail that Newgrounds has been missing for years: the artwork in the "listen audio" pages.

The artwork exists, is shown in the link embeds, in the search results, but not in the most important place: the details and listen page. This extension aims to fix this. It does tiny modifications to the webpage, but enough to be useful, and hides pretty well into Newgrounds's old school website theme.