mm: display song numbers in dmenu

I forgot that the scripts expects a number as output, not the name.
mm: add dummy "-" pattern to match all songs

To have `mm -` list all songs as bare `mm` is already taken – will have
to reconsider that though.
mm: fuck yeah unicode

Use the en dash in tty as well; works just fine in console too.
mm: sort songs using UCA
Revert "mm: sort songs using UCA"

The numbers are now random; the order is a bit unexpected; not to
mention it's /slow/. Like, taking a whole second to sort ~1000 items.

This reverts commit e4f31ee00c7b9042754d39a0c029ae7b6af34118.