phpBB Oauth V1 Wrapper Support

Hello,

I needed some update on PhpBB 3.1.8 OAuth Wrapper to enable twitter OAuth V1.

I simply updated the oauth.php file to handle V1 and V2 type of callback queries.

Then I changed how the token_storage.php work with unique user / session_id fields to store token temporarily (needed to match the exact session for Token Secret changing each query)

And lastly I provide my example for Twitter OAuth implementation that rely on OAuth V1 support.

I'm not really a OAuth expert, I hope this can match most Oauth V1 providers, it should not change any behavior in OAuth V2...