Update changelog re @EnableAspectJAutoProxy

Issue: SPR-8138

Author: cbeams

build-spring-framework/resources/changelog.txt

@@ -12,6 +12,7 @@ Changes in version 3.1 RC1 (2011-10-11)
 * updated JBossLoadTimeWeaver to automatically detect and support JBoss AS 7 as well
 * added support for Hibernate 4.0 (HibernateJpaDialect as well as natively in orm.hibernate4)
 * prepared Spring's DataSource and RowSet adapters for forward compatibility with JDBC 4.1
+* introduced @EnableAspectJAutoProxy
 * introduced ForkJoinPoolFactoryBean for Java 7 (alternative: add new jsr166.jar to Java 6)
 * introduced extended WritableResource interface
 * DefaultListableBeanFactory is only deserializable through a SerializedBeanFactoryReference