Improved OAuth errors handling
feature #47 Improved OAuth errors handling (tucksaun)

This PR was squashed before being merged into the 3.x-dev branch (closes #47).

Discussion
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Improved OAuth errors handling

As discussed @lyrixx, we now rely on the `DefaultAuthenticationFailureHandler` of Symfony which handles redirection in a clean way and as our work in `ConnectAuthenticationFailureHandler` is already handled in `AbstractAuthenticationListener` which is already extended by `ConnectAuthenticationListener`
To be able to do that we need to make `OAuthException` extends `AuthenticationException`

Commits
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51fbc5b Improved OAuth errors handling
Use Guzzle instead of Buzz