HDFS-4629. Using com.sun.org.apache.xml.internal.serialize.* in XmlEditsVisitor.java is JVM vendor specific. Breaks IBM JAVA -pom indentation

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1614673 13f79535-47bb-0310-9956-ffa450edef68