spree/spree — pull request #4176 by paultyng (2014-01-07 23:59:52+00:00)
Title: States are not required in some European countries

See:

* http://en.wikipedia.org/wiki/Address_(geography)#Switzerland
* http://bitboost.com/ref/international-address-formats/switzerland/
* http://geneva.angloinfo.com/information/housing/post-codes/

And other online sources. May need to review additional countries referenced in d0585271b7bc8a285b7ffdbeb1af45bdfece1e22