Follow s6's example directory structure for init

This pulls in the dependencies s6-linux-utils and s6-portable-utils
until they can be evaluated and compared to what Busybox or Toybox has
to offer. Plus the default init scripts rely on them, and I've just
brought them in verbatim (to be updated shortly).
Create the mount points according to the s6 example
More progress on mirroring s6's example configuration

This is getting a bit rediculous and I could probably simplify, but
I wanted to make sure things work as the example showed before making my
own way.