Travel-Status-DE-VRR-1.04.tar.gz (signature)

• Add ->key accessor to Travel::Status::DE::VRR::Line (meaning is unknown)
• Add ->is_cancelled accessor to Travel::Status::DE::VRR::Result
• Travel::Status::DE::VRR::Result->delay will no longer return -9999 for cancelled departures, check ->is_cancelled instead
• Allow Travel::Status::DE::VRR::Line and TraveL::Status::DE::VRR::Result to be serialized to JSON (via TO_JSON method)