LAN hosting and world sharing mods force the config of the host onto everyone, when, in a lot of cases, the host may want others to be able to use a feature, but not want to use it themselves.

By default, the configuration UI would look the same, but modify the client config. A button would allow you to edit the server config instead, which also would remove all the client-only options from the screen while active.

Basically depends on #307, since we'd be storing two config files now.

On this front, ActiveConfig and ClientActiveConfig are properly split now, and the config GUI allows customizing between the two. Things left:

• Clean up config syncing while in-game such that the server config is only propagated if the server one is changed.
• Massive amounts of testing

Ready for merge alongside #307. Further tracking will be done there in terms of Minecraft versions it's propagated to.

Work for this is being done in the config-refactor branch. At the moment, the biggest aspect of work to be done is migrating things such that ActiveConfig and ClientActiveConfig are properly split, instead of everything using ClientActiveConfig.

Downported to all the other versions, this is finally squashed!