curl_version(3) on macOS

The text c9d3c5e0e66d, as Mac OS X 10.7.5, Mac OS X 10.7.4, Mac OS X 10.7.3, Mac OS X 10.7.2, Mac OS X 10.7.1, Mac OS X 10.7 shipped it.

returns the libcurl version string

curl_version(3) on macOS now