implement rotationdelta

[nunq]

the current way we refresh/update the data doesn't work for this feature. currently, we basically do all the calculating, etc. after a match starts, but then we can't get the current x power anymore.
i.e. we need to poll more than once.

so either we do manual polling (x2) or interval polling (auto refreshing™), but since i'm not sure if there's info on if the player is currently in battle (etc.), i'm opting for option 1.