fork() -> vfork()
fork() -> vfork()

This would have been commit #2 which was "Obtained from: BSD/OS" except
their code is buggy (they call err() if the execl() fails, which will
incorrectly call exit()), so instead this is:

Obtained from:	NetBSD

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase