No-cache HTTP response headers added to appropriate web-client servlets.

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@5827 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/web/app/servlet/ExternalAccessServlet.java

@@ -100,6 +100,8 @@ public class ExternalAccessServlet extends BaseServlet
          return;
       }
       
+      setNoCacheHeaders(res);
+      
       uri = uri.substring(req.getContextPath().length());
       StringTokenizer t = new StringTokenizer(uri, "/");
       int tokenCount = t.countTokens();