support for the address persist stuff. Only merge in 2-1-stable when https://github.com/spree/spree/pull/4028 is merged in spree 2-1-stable
Clear out rails dynamic method deprecation warnings
Only require Core::UserAddress above Spree 2.1.3

Allow users on that version to run update this extension and run the
application without issues. e.g. unitialized constant Core::UserAddress
Remove 'sign_in' block and make after filter work again

Fixes #143