require the whole of Active Support's core extensions

this is a follow-up to #318

lib/ransack.rb

@@ -1,3 +1,5 @@
+require 'active_support/core_ext'
+
 require 'ransack/configuration'
 
 module Ransack

lib/ransack/adapters/active_record/base.rb

@@ -1,5 +1,3 @@
-require 'active_support/core_ext/class/attribute'
-
 module Ransack
   module Adapters
     module ActiveRecord

lib/ransack/configuration.rb

@@ -1,5 +1,3 @@
-require 'active_support/core_ext/module/attribute_accessors'
-
 require 'ransack/constants'
 require 'ransack/predicate'
 

lib/ransack/nodes/attribute.rb

@@ -1,5 +1,3 @@
-require 'active_support/core_ext/module/delegation'
-
 module Ransack
   module Nodes
     class Attribute < Node

lib/ransack/nodes/grouping.rb

@@ -1,5 +1,3 @@
-require 'active_support/core_ext/module/delegation'
-
 module Ransack
   module Nodes
     class Grouping < Node

lib/ransack/nodes/node.rb

@@ -1,6 +1,3 @@
-require 'active_support/core_ext/class/attribute'
-require 'active_support/core_ext/module/delegation'
-
 module Ransack
   module Nodes
     class Node

lib/ransack/nodes/value.rb

@@ -1,5 +1,3 @@
-require 'active_support/core_ext/module/delegation'
-
 module Ransack
   module Nodes
     class Value < Node

lib/ransack/ransacker.rb

@@ -1,5 +1,3 @@
-require 'active_support/core_ext/module/delegation'
-
 module Ransack
   class Ransacker
 

lib/ransack/search.rb

@@ -1,5 +1,3 @@
-require 'active_support/core_ext/module/delegation'
-
 require 'ransack/nodes'
 require 'ransack/context'
 require 'ransack/naming'