if the initial open fails with EFTYPE. if a different database
format is found to be more efficient, just add the code to open it
prior to that of the other formats; this maintains backward
compatibility with older databases whilst providing new functionality...
- add rcsid's
- Do what the manual page says; don't create the log file if it does not exist.
- Limited support for ypserv v1; apparently sunos4 clients use it and sunos5
server provides the same.