PHPCSDev ruleset: allow for more than one @since tag

... to document a class's changelog.

Author: jrfnl

PHPCSDev/ruleset.xml

@@ -174,6 +174,9 @@
 
         <!-- Having a @see or @internal tag before the @category tag is fine. -->
         <exclude name="PEAR.Commenting.ClassComment.CategoryTagOrder"/>
+
+        <!-- Using @since for class changelog demands multiple tags. -->
+        <exclude name="PEAR.Commenting.ClassComment.DuplicateSinceTag"/>
     </rule>
 
 </ruleset>