Extend Action with redirect after login logic, update some actions to use it

lib/action.php

@@ -60,6 +60,7 @@ class Action extends HTMLOutputter // lawsuit
     protected $ajax = false;
     protected $menus = true;
     protected $needLogin = false;
+    protected $redirectAfterLogin = false;
     protected $needPost = false;    // implies canPost if true
     protected $canPost = false;     // can this action handle POST method?
 
@@ -248,6 +249,10 @@ class Action extends HTMLOutputter // lawsuit
         if ($this->needLogin) {
             $this->checkLogin(); // if not logged in, this redirs/excepts
         }
+        
+        if ($this->redirectAfterLogin) {
+            common_set_returnto($this->selfUrl());
+        }
 
         $this->updateScopedProfile();