added "flush()" method to TransactionStatus and TransactionSynchronization interfaces; test context manager automatically flushes transactions before rolling back; general polishing of transaction management code

org.springframework.jdbc/src/test/java/org/springframework/jdbc/datasource/DataSourceTransactionManagerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -1958,6 +1958,9 @@ public class DataSourceTransactionManagerTests extends TestCase {
 		public void resume() {
 		}
 
+		public void flush() {
+		}
+
 		public void beforeCommit(boolean readOnly) {
 			if (this.status != TransactionSynchronization.STATUS_COMMITTED) {
 				fail("Should never be called");