Allow file_put_contents and readfile

Author: derpaschi

Required/ruleset.xml

@@ -89,7 +89,7 @@
 		<properties>
 			<property name="exclude" type="array">
 				<!-- Allow the use of filesystem functions. -->
-				<element value="file_get_contents"/>
+				<element value="file_get_contents,file_put_contents,readfile"/>
 				<!-- wp_json_encode() is nowadays only a simple wrapper for json_encode(). -->
 				<element value="json_encode"/>
 			</property>