technique) so that we don't wind up calling into an application's
version if the application defines them.
Inspired by: qpopper's interfering and buggy version of strlcpy
whether a named utility should behave in FreeBSD 4.x-compatible mode
or in a standard mode (default standard). The configuration is done
malloc(3)-style, with either an environment variable or a symlink.
Update expr(1) to use this new interface.