Makes BeanDefinitionUtils final with private constructor.

Closes #1850
Original pull request #2167

Author: Manousos Mathioudakis

src/main/java/org/springframework/data/jpa/util/BeanDefinitionUtils.java

@@ -44,11 +44,13 @@
  * @author Oliver Gierke
  * @author Mark Paluch
  */
-public class BeanDefinitionUtils {
+public final class BeanDefinitionUtils {
 
 	private static final String JNDI_OBJECT_FACTORY_BEAN = "org.springframework.jndi.JndiObjectFactoryBean";
 	private static final List<Class<?>> EMF_TYPES;
 
+	private BeanDefinitionUtils() {}
+
 	static {
 
 		List<Class<?>> types = new ArrayList<Class<?>>();