Split configuration constants into local XConfigUtils classes instead of piling them up in AnnotationConfigUtils

spring-tx/src/main/java/org/springframework/transaction/config/TransactionManagementConfigUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -17,6 +17,8 @@
 package org.springframework.transaction.config;
 
 /**
+ * Configuration constants for internal sharing across subpackages.
+ *
  * @author Chris Beams
  * @since 3.1
  */