Should probably be fixed up, I've only hacked up @dkerr64's version for acme.sh to work on my local instance. It assumes you're using curl, I didn't bother stealing acme.sh's whole library of functions.

DNS_ADD_COMMAND="~/.getssl/dns_freedns.sh add"
DNS_DEL_COMMAND="~/.getssl/dns_freedns.sh rm"

Pipe the commands to nsupdate

This adds a dot in front of the fqdn and the zone name, so the
comparison will only check against full DNS parts of the fqdn and the
zone name. This will prevent to match a fqdn against an unrelated zone
name which overlaps with the wanted zone in the naming.

Fixes #398

Allow to remove only selected token for subdomain.

Added secondary #s to the default config, so that when the lines are uncommented, the function properly.