MIN and MAX #def's with different () now use longest () version.

../include/os.h redefines _PATH_VI, from /usr/include/paths.h in some cases:
/* Apparently VI has become the standard editor for UNIX. */
os.h:
#ifndef _PATH_VI
# define _PATH_VI		"/usr/bin/vi"
#endif

paths.h:
#define _PATH_VI        "/bin/vi"

