Add some more acks.

Author: tabatkins

css-variables/Overview.html

@@ -813,7 +813,8 @@ <h2 class=no-num id=acknowledgments>Acknowledgments</h2>
 
   <p>Thanks to Daniel Glazman and Dave Hyatt for writing the original
    Variables draft in 2008. Thanks to many WG members for keeping the idea of
-   variables alive through the years.
+   variables alive through the years. Thanks to Roland Steiner and Luke
+   Macpherson for invaluable feedback and implementation experience.
 
   <h2 class=no-num id=references>References</h2>
 

css-variables/Overview.src.html

@@ -478,7 +478,7 @@ <h3 id="cr-exit-criteria">
 
 <h2 class=no-num id="acknowledgments">Acknowledgments</h2>
 
-	<p>Thanks to Daniel Glazman and Dave Hyatt for writing the original Variables draft in 2008.  Thanks to many WG members for keeping the idea of variables alive through the years.</p>
+	<p>Thanks to Daniel Glazman and Dave Hyatt for writing the original Variables draft in 2008.  Thanks to many WG members for keeping the idea of variables alive through the years.  Thanks to Roland Steiner and Luke Macpherson for invaluable feedback and implementation experience.</p>
 
 <h2 class=no-num id="references">References</h2>