[AddressBundle] Don't validate province if no country was set
Merge pull request #2076 from stloyd/bugfix/province_validator

[AddressBundle] Don't validate province if no country was set
[ResourceBundle]  added the ability to configure services, forms, twig extensions, validations and mapping using yml or xml files (or both)
[CoreBundle] Fixed problem when this bundle is configured to load YAML files.