INT-4528: Docs for SmartLifecycleRoleController

JIRA: https://jira.spring.io/browse/INT-4528

Author: artembilan

src/reference/asciidoc/endpoint.adoc

@@ -664,6 +664,17 @@ See the http://docs.spring.io/spring-framework/docs/current/spring-framework-ref
 Starting with version 4.2, endpoints can be assigned to roles.
 Roles let endpoints be started and stopped as a group.
 This is particularly useful when using leadership election, where a set of endpoints can be started or stopped when leadership is granted or revoked, respectively.
+For this purpose the framework registers a `SmartLifecycleRoleController` bean in the application context with the name `IntegrationContextUtils.INTEGRATION_LIFECYCLE_ROLE_CONTROLLER`.
+Whenever it is necessary to control lifecycles, this bean can be injected or `@Autowired`:
+
+====
+[source, xml]
+----
+<bean class="com.some.project.SomeLifecycleControl">
+    <property name="roleController" ref="integrationLifecycleRoleController"/>
+</bean>
+----
+====
 
 You can assign endpoints to roles using XML, Java configuration, or programmatically.
 The following example shows how to configure endpoint roles with XML:
@@ -734,11 +745,9 @@ Invoking `roleController.startLifecyclesInRole("cluster")` and the corresponding
 
 NOTE: Any object that implements `SmartLifecycle` can be programmatically added -- not just endpoints.
 
-The `SmartLifecycleRoleController` implements `ApplicationListener<AbstractLeaderEvent>` and it automatically
-starts and stops its configured `SmartLifecycle` objects when leadership is granted or revoked (when some bean publishes
-`OnGrantedEvent` or `OnRevokedEvent`, respectively).
+The `SmartLifecycleRoleController` implements `ApplicationListener<AbstractLeaderEvent>` and it automatically starts and stops its configured `SmartLifecycle` objects when leadership is granted or revoked (when some bean publishes `OnGrantedEvent` or `OnRevokedEvent`, respectively).
 
-IMPORTANT: When using leadership election to start and stop components, it is important to set the `auto-startup` XML attribute (`autoStartup` bean property) to `false` so taht the application context does not start the components during context initialization.
+IMPORTANT: When using leadership election to start and stop components, it is important to set the `auto-startup` XML attribute (`autoStartup` bean property) to `false` so that the application context does not start the components during context initialization.
 
 Starting with version 4.3.8, the `SmartLifecycleRoleController` provides several status methods: