add china_city gem.
init china_city.
add convenient css method: margin-right.
add event order shipping address model.
save order address in model and controller.
save order address.
fixed rspec error.
merge master.
validate shipping address at server.
validate order quantity and address on create.
Merge pull request #511 from saberma/saberma-feature/463-save-order-shipping-address

用户可以录入发票收货地址等信息 #463