Merge pull request #8683 from bwajtr:1.5.x

* pr/8683:
  Polish "Add support for HotSwapAgent to devtools"
  Add support for HotSwapAgent to devtools

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/restart/AgentReloader.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -36,6 +36,7 @@ public abstract class AgentReloader {
 		Set<String> agentClasses = new LinkedHashSet<String>();
 		agentClasses.add("org.zeroturnaround.javarebel.Integration");
 		agentClasses.add("org.zeroturnaround.javarebel.ReloaderFactory");
+		agentClasses.add("org.hotswap.agent.HotswapAgent");
 		AGENT_CLASSES = Collections.unmodifiableSet(agentClasses);
 	}