The EntityResolver should be invoked when jdk.xml.resolveExternalEntities is set to true and should not be invoked when the property has been set to false. Enhancing the tests to check for this expected behaviour.

git-svn-id: https://svn.apache.org/repos/asf/xerces/java/branches/xml-schema-1.1-dev@1564518 13f79535-47bb-0310-9956-ffa450edef68