Revert deprecation of AbstractSingletonPFB and co

Removed formal deprecation warnings for AbstractSingletonFactoryBean and
its TransactionProxyFactoryBean and CacheProxyFactoryBean subclasses.

This is principally because TPFB is still used by Grails and could
conceivably be used to good effect by any third-party framework in a
similar fashion. CPFB is new with 3.1, but similar use is predictable.

Deprecations have been replaced by strong recommendations that users
avoid these types in modern Spring applications and favor the use of
namespaces and annotatinos, such as tx: and @Transactional (around
since Spring 2.x) and cache: and @Cacheable.

Issue: SPR-8680, SPR-8686

org.springframework.aop/src/main/java/org/springframework/aop/framework/AbstractSingletonProxyFactoryBean.java

@@ -27,23 +27,16 @@ import org.springframework.beans.factory.InitializingBean;
 import org.springframework.util.ClassUtils;
 
 /**
- * Convenient superclass for proxy-creating
- * {@link org.springframework.beans.factory.FactoryBean FactoryBean} types that produce
- * only singleton-scoped objects.
- * 
+ * Convenient superclass for {@link FactoryBean} types that produce singleton-scoped
+ * proxy objects.
+ *
  * <p>Manages pre- and post-interceptors (references, rather than
  * interceptor names, as in {@link ProxyFactoryBean}) and provides
  * consistent interface management.
  *
  * @author Juergen Hoeller
  * @since 2.0
- * @deprecated as of Spring 3.1 following the deprecation of its only implementation
- * ({@link org.springframework.transaction.interceptor.TransactionProxyFactoryBean
- * TransactionProxyFactoryBean}) and generally in favor of providing such functionality
- * via Spring XML namespaces, e.g. {@code tx:} or {@code @Enable}&#042; annotations, e.g.
- * {@code @EnableTransactionManagement}.
  */
-@Deprecated
 @SuppressWarnings("serial")
 public abstract class AbstractSingletonProxyFactoryBean extends ProxyConfig
 		implements FactoryBean<Object>, BeanClassLoaderAware, InitializingBean {