Include the features when ActionController::Base is loaded

This will make this gem not load order dependent.

See rails/actionpack-page_caching#6 (comment)

Author: pixeltrix

CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Fix load order problem with other gems
+
+    *Andrew White*
+
 ## 1.1.0
 
 *   Allow to use non-proc object in `cache_path` option. You can pass an object that

lib/action_controller/action_caching.rb

@@ -1,3 +1,5 @@
+require 'action_controller/caching/actions'
+
 module ActionController
   module Caching
     eager_autoload do
@@ -7,3 +9,5 @@ module Caching
     include Actions
   end
 end
+
+ActionController::Base.send(:include, ActionController::Caching::Actions)

lib/actionpack/action_caching/railtie.rb

@@ -0,0 +1,13 @@
+require 'rails/railtie'
+
+module ActionPack
+  module ActionCaching
+    class Railtie < Rails::Railtie
+      initializer 'action_pack.action_caching' do
+        ActiveSupport.on_load(:action_controller) do
+          require 'action_controller/action_caching'
+        end
+      end
+    end
+  end
+end