Allow to build with the PyPI package "clang" instead of "libclang". 1. It seems to be maintained. 2. In the FreeBSD base system there is no pre-built libclang.so. If you need this library you have to install llvm from ports additionally. 2. On FreeBSD there is no pre-built wheel "libclang" with a packaged libclang.so.

Long: speed-limit
Short: Y
Arg: <speed>
Help: Stop transfers slower than this
---
If a download is slower than this given speed (in bytes per second) for
speed-time seconds it gets aborted. speed-time is set with --speed-time and is
30 if not set.

If this option is used several times, the last one will be used.