INT-575, Added the following to MapToObjectTransformer:

1. Javadoc
2. Added check to only allow 'prototype' beans to be specified during the construction
3. Made sure that instance of the transformed Object is created only during the transformation

org.springframework.integration/src/test/java/org/springframework/integration/transformer/MapToObjectTransformerTests.java

@@ -64,7 +64,7 @@ public class MapToObjectTransformerTests {
 	}
 	@SuppressWarnings("unchecked")
 	@Test(expected=MessageTransformationException.class)
-	public void testMapToObjectTransformationWithSingleton(){
+	public void testMapToObjectTransformationNonPrototype(){
 		Map map = new HashMap();
 		map.put("fname", "Justin");
 		map.put("lname", "Case");