Add support for regions

- Add region id to RepositoryState and hook it
  via RepositoryStateMachineModelFactory.
- Relates to #262

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryState.java

@@ -48,6 +48,13 @@ public abstract class RepositoryState extends BaseRepositoryEntity {
 	 */
 	public abstract String getState();
 
+	/**
+	 * Gets the region.
+	 *
+	 * @return the region
+	 */
+	public abstract String getRegion();
+
 	/**
 	 * Checks if is initial.
 	 *

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryStateMachineModelFactory.java

@@ -135,7 +135,8 @@ public class RepositoryStateMachineModelFactory extends AbstractStateMachineMode
 			}
 
 			RepositoryState parentState = s.getParentState();
-			StateData<String, String> stateData = new StateData<String, String>(parentState != null ? parentState.getState() : null, null,
+			Object region = s.getRegion();
+			StateData<String, String> stateData = new StateData<String, String>(parentState != null ? parentState.getState() : null, region,
 					s.getState(), s.isInitial());
 			stateData.setStateActions(stateActions);
 			stateData.setEntryActions(entryActions);