Don't hardcode the path to svlogd either

The hardcoded paths to non-runit programs are probably ill-advised too; I'll
remove all of those if something breaks later. For now they're working fine.
mingetty *must* be process group leader to work.

Same goes for agetty, but that doesn't _crash_ if it isn't...
Add runscript for bind9 named

It seems the OpenRC init script for this is broken. As in it'll hang
indefinitely if (wild guessing here) it's configured to listen on an address
that isn't yet configured. Which happens to be the case on my router running
quagga+hostapd, where the named script tries to preempt both of those.

I don't have the patience to debug that kind of bullshit on a headless machine
right now, so I'll just replace it with a short shell script.