Class org.apache.hadoop.conf.Configuration

Added Methods
String substituteCommonVariables(String)	Provides a public wrapper over substituteVars in order to avoid compatibility issues.
void writeXml(String, Writer, Configuration)	Write out the non-default properties in this configuration to the given Writer When property name is not empty and the property exists in the configuration this method writes the property and its attributes to the Writer When property name is null or empty this method writes all the configuration properties and their attributes to the Writer When property name is not empty but the property doesn't exist in the configuration this method throws an IllegalArgumentException