Add http client to v0.4 announcement

doc/v0.4_announcement.html

@@ -31,6 +31,8 @@
       <code>Stream.prototype.pipe()</code> method. Functionality was
       enhanced and API simplified.
 
+      <li>Simplier HTTP client API with connection pools.
+
       <li> Cheaper <code>Buffer</code> allocation. Node uses
       <code>Buffer</code> objects in many places - it was noticed that they
       were relatively slow to allocate and difficult to garbage collect. The