datanucleus.xml 3.2.1 XSLT TransformerFactory regression.

org.datanucleus.store.xml.ConnectionFactoryImpl$ManagedConnectionImpl.close calls the release() method:

        public void release()
        {
            if (commitOnRelease)
            {
                try
                {
                    TransformerFactory tf = TransformerFactory.newInstance();
                    tf.setAttribute("indent-number", indent);

However, "indent-number" is not supported; OutputKeys.INDENT should be used
(see http://stackoverflow.com/questions/15134861/java-lang-illegalargumentexception-not-supported-indent-number).

Produces stack trace on retrieve/get:

java.lang.IllegalArgumentException: Unknown attribute indent-number
        at net.sf.saxon.Configuration.setConfigurationProperty(Configuration.java:2185) ~[saxon-8.7.jar:na]
        at net.sf.saxon.TransformerFactoryImpl.setAttribute(TransformerFactoryImpl.java:342) ~[saxon-8.7.jar:na]
        at org.datanucleus.store.xml.ConnectionFactoryImpl$ManagedConnectionImpl.close(ConnectionFactoryImpl.java:194) ~[datanucleus-xml-3.2.1.jar:na]
        at org.datanucleus.store.connection.ConnectionManagerImpl$2.transactionCommitted(ConnectionManagerImpl.java:413) [datanucleus-core-3.2.11.jar:na]
        at org.datanucleus.TransactionImpl.internalPostCommit(TransactionImpl.java:554) [datanucleus-core-3.2.11.jar:na]
        at org.datanucleus.TransactionImpl.commit(TransactionImpl.java:335) [datanucleus-core-3.2.11.jar:na]
        at org.datanucleus.api.jdo.JDOTransaction.commit(JDOTransaction.java:98) [datanucleus-api-jdo-3.2.7.jar:na]