Network management software should order itself after network-pre.target
(man 7 systemd.special) so that other units can order themselves before
the *beginning* of network initialization. (qubes-misc-post too because
it calls setup-ip.)
Relevant for QubesOS/qubes-issues#2108
Get rid of underscores in filenames, use dashes instead.
This is first part of cleanup in filenames.
"qubes_rpc" still untouched - will be in separate commit.
