Previously, `get_matches` would return even if --help or --version was
given, and we could check for them manually. That behavior seems to have
changed. Instead, we must use get_matches_safe to inspect the error to
determine what happened.
We can't use the same process for -V/--version since clap will
unconditionally print its own version info. Instead, we rename (internally)
the version flag so that clap doesn't interfere.
95bc678403