Rails.initialized? can be called at any time without raising an excep…

…tion [Closes #2507]

Changes:

* `Rails.initialized=` has been removed
* `Rails.initialized?` and `Rails.application.initialized?` are now
* delegating to `MyApp::Application.initialized?`

railties/lib/rails.rb

@@ -42,11 +42,7 @@ def initialize!
     end
 
     def initialized?
-      @@initialized || false
-    end
-
-    def initialized=(initialized)
-      @@initialized ||= initialized
+      application.initialized?
     end
 
     def logger

railties/lib/rails/application.rb

@@ -134,6 +134,10 @@ def initialize!(group=:default) #:nodoc:
       self
     end
 
+    def initialized?
+      @initialized
+    end
+
     # Load the application and its railties tasks and invoke the registered hooks.
     # Check <tt>Rails::Railtie.rake_tasks</tt> for more info.
     def load_tasks(app=self)

railties/test/application/loading_test.rb

@@ -285,6 +285,16 @@ def show
     assert_equal 'OK', last_response.body
   end
 
+  def test_initialize_can_be_called_at_any_time
+    require "#{app_path}/config/application"
+
+    assert !Rails.initialized?
+    assert !AppTemplate::Application.initialized?
+    Rails.initialize!
+    assert Rails.initialized?
+    assert AppTemplate::Application.initialized?
+  end
+
   protected
 
   def setup_ar!