This incarnation is written in the user namespace as opposed to
the previous one which was done in kernel namespace. Also, rump
does all the handshaking now instead of excepting an application
to come up with the user namespace socket.
There's still a lot to do, including making code "a bit" more
robust, actually running different clients in a different process
inside the kernel and splitting the client side library from librump.
I'm committing this now so that I don't lose it, plus it generally
works as long as you don't use it in unexcepted ways: i've tested
ifconfig(8), route(8), envstat(8) and sysctl(8).
b1842c2201