Apply Some Java 8 Code Changes

* Make most functional interfaces as `@FunctionalInterface`
* Convert some abstract classes to `@FunctionalInterface` with `default` methods
* Apply Lambda style implementation in some places
* Remove `Function` in favor of similar in Java 8

*  Remove redundant code from `DefaultAmqpHeaderMapper` since we are already on Spring AMQP-2.0
* Add several ctors to the `ExpressionEvaluatingMessageListProcessor`
* Populate explicit `Boolean.class` `expectedType` from the `ExpressionEvaluatingReleaseStrategy`

spring-integration-redis/src/main/java/org/springframework/integration/redis/outbound/ArgumentsStrategy.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import org.springframework.messaging.Message;
  * @author Artem Bilan
  * @since 4.0
  */
+@FunctionalInterface
 public interface ArgumentsStrategy {
 
 	Object[] resolve(String command, Message<?> message);