Finally got around to installing OpenBSD (rev 3.3) in a vmware partition.
Found that several #if BSD's were inappropriate for modern BSD's. Haven't
installed FreeBSD or NetBSD, but based on reading their man pages,
these changes are needed there too. Mostly due to POSIX time() signature.
Switch the default Linux build behavior to use random instead of lrand48,
since lrand48 exhibits some obviously non-random behavior. random() has
been in glibc for a long time. Even if no other changes are made to
nethack's random number generator, this will improve the Linux behavior.
