Arch Linux

The bundled waf of upstreams is a known issue and prone to be outdated.

Devendoring the use of bundled waf allows us to centrally patch one version and rely on a centrally available version instead of many varying versions.

In many cases it is enough to remove the local `waf/` directory and call `waf` instead of `./waf` (after adding waf to makedepends).

In some cases the use of waf may require a more hands on approach with patches or further customizations to ensure, that the local wscript file works with the system-provided waf.
See current waf dependents for inspiration: https://archlinux.org/packages/extra/any/waf/