Test: Joining and leaving Kyoto

[tumblerer]

Need to test how leaving and joining kyoto behaves.

Particularly with reference to how emission targets and maintained and recalculated.

[sc1109]

Rejoining is very difficult due to the number of lists you need to be added to at the right time. Me and Tory think we should forbid rejoining for now, is this devastating to anyone?

[cmd08]

Fine, rejoining is in the next build.