World|Client: Revised ClientSubsector boundary data schema
Added ClientSubsector::EdgeRing and revised internal bookkeeping so that complete boundary data is available (for directly targeting of dependent Surfaces for redecoration, and neighbor plane mapping).
Next step: Handle missing material fixes at ring level. Todo: Cleanup
World|Client: Revised ClientSubsector boundary data schema
Added ClientSubsector::EdgeRing and revised internal bookkeeping so
that complete boundary data is available (for directly targeting of
dependent Surfaces for redecoration, and neighbor plane mapping).
Next step: Handle missing material fixes at ring level.
Todo: Cleanup