Allow to add classes for external and mail links

Let's start with this one! Definitely doable in a timely manner.

After a whole lot of work this is finally up and running! To review it is!

This time we might be done!

Just some final alignments.

Please also add tests like the module already has.

With all of it working out fine now, I hope that was the last from me! :)

Well done! Nice and helpful feature!

Merged! :)

Automatically closed - issue fixed for 2 weeks with no activity.

This issue had a hook_update that referenced non-existent config options. I've opened 🐛 extlink_update_8103 for mailto & ext links define a non-used setting Active to fix the update hook. An MR is posted over there.

Ouch, thank you @heddn. No idea why I didn't see that! -.-