distributed memoizer added to ensure absolute duplicate posts don't get through

in case of an absolute dupe just return the memoized post

This works around issues with wordpress being crazy

spec/controllers/posts_controller_spec.rb

@@ -282,6 +282,18 @@ describe PostsController do
         ::JSON.parse(response.body).should be_present
       end
 
+      it 'protects against dupes' do
+        # TODO we really should be using a mock redis here
+        xhr :post, :create, {raw: 'this is a test post 123', title: 'this is a test title 123', wpid: 1}
+        response.should be_success
+        original = response.body
+
+        xhr :post, :create, {raw: 'this is a test post 123', title: 'this is a test title 123', wpid: 2}
+        response.should be_success
+
+        response.body.should == original
+      end
+
       context "errors" do
 
         let(:post_with_errors) { Fabricate.build(:post, user: user)}