CURLOPT_RESUME_FROM(3) on macOS

The text 46c5d7dd32f7, as OS X 10.11.6, OS X 10.11.5, OS X 10.11.4, OS X 10.11.3, OS X 10.11.2, OS X 10.11.1, OS X 10.11, OS X 10.10.5 shipped it.

set a point to resume transfer from

CURLOPT_RESUME_FROM(3) on macOS now