Update for change to Persistent's default value setup.
Integrate latest round of ThiefLib features. Switch all GenericMessage& handlers to Message&.
KDTransitionTrap: remove; replaced by Thief::Transition helper class.
KDTrapFog, KDTrapWeather, KDSyncGlobalFog: migrate to Thief::Transition.
*: provide default values for message data where appropriate.