macOS and (AFAICT) most Linux distributions ship with the Info-ZIP
version of unzip, which has the `unzip -h` flag; but other
implementations of unzip do not necessarily have it (i.e. FreeBSD).
`unzip` under FreeBSD does not support `unzip -h`. Under both Linux and
FreeBSD, `unzip -v` presents the list of options, though. Using this
instead of `unzip -h` to detect the Debian-patched version of the
Info-ZIP unzip program.