INT-4390: Fix tangles

JIRA: https://jira.spring.io/browse/INT-4390

Phase I: flow context/registration cycle

- extract interfaces
- rename implementations to `Standard...`

Phase II - dsl<->dsl.channel tangles

Move the channel specs to dsl.

Fix missing refactorings

(Not related to DSL) - rename core `event` package to `events`

- avoid collision with event module package
- fix tangle caused by `MessageGroupExpiredEvent`.

Phase III - dsl<->config.dsl

- move classes from config.dsl to dsl

(Not related to DSL) - fix many tangles caused by graph being a sub-package of support.management
 - make `graph` a top-level package

(Not related to DSL) - move `IntegrationManagementConfigurer` from
`management` to `config` - tangle between core and management
* Polishing Copyrights, diamonds, some JavaDocs and What's New

spring-integration-ip/src/test/java/org/springframework/integration/ip/dsl/IpIntegrationTests.java

@@ -41,7 +41,7 @@ import org.springframework.integration.dsl.IntegrationFlow;
 import org.springframework.integration.dsl.IntegrationFlows;
 import org.springframework.integration.dsl.Transformers;
 import org.springframework.integration.dsl.context.IntegrationFlowContext;
-import org.springframework.integration.dsl.context.IntegrationFlowRegistration;
+import org.springframework.integration.dsl.context.IntegrationFlowContext.IntegrationFlowRegistration;
 import org.springframework.integration.ip.tcp.TcpReceivingChannelAdapter;
 import org.springframework.integration.ip.tcp.TcpSendingMessageHandler;
 import org.springframework.integration.ip.tcp.connection.AbstractClientConnectionFactory;
@@ -60,6 +60,7 @@ import org.springframework.test.context.junit4.SpringRunner;
 
 /**
  * @author Gary Russell
+ *
  * @since 5.0
  *
  */