v2.0.0

Port to RT 6.0 (breaking change, drops RT 4.x support).

• requires_rt 6.0.0
• LastUpdater and LastUpdater.* keep working via the unchanged Tickets_Local.pm overlay/FIELD_METADATA mechanism
• LastUpdater is now also selectable in the ticket Query Builder's Watcher field dropdown

v1.0.0

Last release before the RT6 rewrite.