Revert "removecomments"

This reverts commit 6ee1468ce3.

lib/is_commentable.rb

@@ -0,0 +1,20 @@
+module IsCommentable
+  def self.included(base)
+    base.class_eval do
+      include InstanceMethods
+      has_many :comments, as: :commentable, dependent: :destroy
+#      extend ClassMethods
+
+    end
+    
+  end
+  module InstanceMethods  
+    def is_commentable?
+      true
+    end
+    def comment(user, text, attr={})
+      comments << Comment.build_for(self, user, text, attr)
+    end
+  end
+
+end