Rather than opening the binding file, checking for advisory lock, reading a

Rather than opening the binding file, checking for advisory lock, reading a
piece of it for the address, opening a socket, and providing the address to
the RPC clnt layer.. do all these steps with the magic system call ypconnect(2)
which performs these steps without other system calls, and provides a socket
which is not readily abuseable for other purposes.
ok jmatthew, miod