This is an implementation of wireguard support using wg-quick config
generation.
This seems preferrable to the existing wireguard support because
it handles many more routing and resolvconf edge cases than the
current wireguard support.
It also includes work-arounds to make key files work.
This has one quirk:
We need to set reverse path checking in the firewall to false because
it interferes with the way wg-quick sets up its routing.