As a User, I only want to see the latest version of each license. E.g. if there was a Creative Commons 3.0 license before, and in the meantime, Creative Commons 4.0 was published, I only want to see 4.0 in the list of licenses when creating/changing events or series. However, if an event/series was published under CC 3.0 already, I still want to see 3.0 as long as I don't change it to 4.0 for that particular event/series.
Also, I would like the licenses to be listed in a meaningful order, which is not necessary alphabetically.