Show region name in login language selection

Since a language may have multiple localizations for various countries, in the login page we should show the locale region name.


Here's the problem (see the multiple *Spanish*)
> ![login-languages-before](https://f.cloud.github.com/assets/928116/316985/c96239b4-9850-11e2-833f-bbb1b379e6be.png)

And here's the result with this pull request
> ![login-languages-after](https://f.cloud.github.com/assets/928116/316987/df511f42-9850-11e2-9953-b4dfa6c3cdb6.png)

And, as a bonus, the language list is sorted alphabetically.