CommonsDelinker should notify Wikipedia communities when removing file from featured contents

[Alaa]

Hello, it's a proposal from arwiki community that CommonsDelinker should notify Wikipedia communities in village pump when removing file from featured content (featured/good article, featured list).

This notification can help to find new files and check that there's no broken files/parameters in this content, as this content consider as the best.

Arwiki community suggest this proposal after this https://bitbucket.org/magnusmanske/commons-delinquent/issues/39/removing-image-from-in-arwiki-leave-image