There's not much point in having uucpd behave differently than
login(1) for this, and now uucpd is compatible to the default chat
script of Taylor UUCP which sends a single \r at first.
While i was at it, added a few strategic ``errno = 0;''s, so at least
an `Undefined error 0' will be returned for things like a closed
connection while reading the login ID or password, as opposed to an
even more bogus thing like `No such file or directory'.