Make province-choices.js more flexible by not relying on .well class

Currently the province-choices.js relies on a parent container for an address to have a .well class,
even though there already is an .address-container class. This PR makes it use the latter.
Merge pull request #613 from Richtermeister/more-flexible-province-js

Make province-choices.js more flexible by not relying on .well class