connection services support

tests/cs.c implements name lookup and other services. It also shows how to
use stuff like /srv and other nice bits. It can look up names via
local ndb files, or dns. And, unlike the horrific nsswitch, it doesn't
require programs to redo the same stuff over and over every time
they run: you just open /srv/cs, push a request, get an answer.
You doh't reopen a bunch of files, and dlopen a bunch of other
files. One read, one write, you got your answer.

It won't work at present because akaros pipes are not bidirectional.
But it at least shows a starting point. We should improve akaros
pipes maybe.

Signed-off-by: Ronald G. Minnich <rminnich@google.com>