interface() calls now push/pop rather than shift/unshift (performance)

lib/class.js

@@ -327,7 +327,7 @@ function createStaging( cname )
  */
 function createImplement( base, ifaces )
 {
-    ifaces.unshift( base );
+    ifaces.push( base );
 
     // Defer processing until after extend(). This also ensures that implement()
     // returns nothing usable.
@@ -602,7 +602,7 @@ var implement = function()
 {
     var args = Array.prototype.slice.call( arguments ),
         dest = {},
-        base = args.shift(),
+        base = args.pop(),
         len  = args.length,
         arg  = null,