Merge branch 'master' into active_model

Conflicts:
	activemodel/lib/active_model/core.rb
	activemodel/test/cases/state_machine/event_test.rb
	activemodel/test/cases/state_machine/state_transition_test.rb
	activerecord/lib/active_record/validations.rb
	activerecord/test/cases/validations/i18n_validation_test.rb
	activeresource/lib/active_resource.rb
	activeresource/test/abstract_unit.rb

1 files changed, 22 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/concern.rb b/activesupport/lib/active_support/concern.rb
new file mode 100644
index 0000000000..154f8807f7
--- /dev/null
+++ b/activesupport/lib/active_support/concern.rb
@@ -0,0 +1,22 @@
+require 'active_support/dependency_module'
+
+module ActiveSupport
+  module Concern
+    include DependencyModule
+
+    def append_features(base)
+      if super
+        base.extend const_get("ClassMethods") if const_defined?("ClassMethods")
+        base.class_eval(&@_included_block) if instance_variable_defined?("@_included_block")
+      end
+    end
+
+    def included(base = nil, &block)
+      if base.nil?
+        @_included_block = block
+      else
+        super
+      end
+    end
+  end
+end