ricardovaleriano/call4paperz — pull request #74 by ricardovaleriano (2014-11-21 13:34:46+00:00)
Title: Twitter registration removal.

Twitter authentication doesn't returns the user's email.
This PR forbidden a registration from twitter, but allow authentication form it if the user already exists.
To make it possible this PR also add the feature for a user associate accounts (google, facebook, twitter etc.) with the current profile.