Add markdown tools to the ban message textarea

Now we can ban in style!
Um, can you use this regex (adds modqueue-type pages):
`/^https?:\/\/(?:[-\w\.]+\.)?reddit\.com\/r\/[\-\w\.]+\/about\/(?:edit|modqueue|reports|spam|banned)\/?/i`

I should have done this when I added comment tools to those pages, but it seems I overlooked the preview entirely (my mistake).