Add a template for users to create custom JAXP configuration files, that can then be used to test and verify the readiness of their applications before the JDK's eventual switch to a more secure configuration by default:

  jaxp-strict.properties.template: this file provides a template for creating custom configuration files. The settings in this file are more restrictive than those in the default configuration, jaxp.properties. A configuration file created based on the template can be set up using the system property `java.xml.config.file` to override the default configuration `jaxp.properties` and used to assess the impact of a stricter configuration.