Files - Show everything in thumbnail view / Non-images not showing in "&view=1"

digibandit

Inside of files, there should at least be a placeholder to show that files that cannot be previewed are still there. Like PDFs.

wrongecho

There are a lot of file types we cannot easily generate thumbnail previews for.

We should either make it clear that those items are omitted from this view, or come up with a placeholder for them (and some extra logic so we don't try to open these in the photo viewer).