ResourceLoaderModule: Add @since annotations to new methods

Change-Id: I91434fcdc87efdf6d49ec94348f26d20c840abad

includes/resourceloader/ResourceLoaderModule.php

@@ -441,6 +441,8 @@ abstract class ResourceLoaderModule {
 	/**
 	 * Helper method for calculating when this module's definition summary was last changed.
 	 *
+	 * @since 1.23
+	 *
 	 * @return int UNIX timestamp or 0 if no definition summary was provided
 	 *  by getDefinitionSummary()
 	 */
@@ -505,6 +507,8 @@ abstract class ResourceLoaderModule {
 	 * contain arrays and scalars as values (avoid object instances) which means
 	 * it requires abstraction.
 	 *
+	 * @since 1.23
+	 *
 	 * @return array|null
 	 */
 	public function getDefinitionSummary( ResourceLoaderContext $context ) {