Fixes #3223.

#### What's this PR do?
- Fixes #3223: UK SSO: newly registered users has wrong country
- Upgrades `external_auth`

#### How should this be manually tested?
- Enable and setup Dosomething UK module
- Run `ds test uk`
![image](https://cloud.githubusercontent.com/assets/672669/4761379/b72366cc-5af7-11e4-86e9-0edabb532ca9.png)

#### What are the relevant tickets?
#3223 — UK SSO: newly registered users has wrong country
#3217 — Fix address field country on DS Canada
dosomething/drupal-external-auth#3 — Passes $form argument to controllers' setup method
dosomething/drupal-external-auth#4 — Pass form state by reference.