GOKZ 3.0.0 support

[walliski]

At the moment the plugin does not support GOKZ 3.0.0. There needs to be changes made to the chat and clantag plugins to make them work properly.

I don't see much value in continuing the local ranks plugin, as the global ranks gives a lot more accurate skill level for users. The use case of having purely local ranks would then be for non-global, or true LAN servers, which I think is a pretty niche use case. So at the moment I do not have any plan of continuing support for this, but PRs are welcome!