Overhaul ProductionBar:

- Is now a conditional trait
- Now respects multiple Production trait instances
- ProductionType is now required

OpenRA.Mods.Common/UpdateRules/UpdatePath.cs

@@ -103,6 +103,7 @@ namespace OpenRA.Mods.Common.UpdateRules
 				new AddRearmable(),
 				new MergeAttackPlaneAndHeli(),
 				new RemovedDemolishLocking(),
+				new RequireProductionType(),
 			})
 		};