Authentication: Facebook

[augustohp]

Add more options for login/register to speakers.
Because OpenId/Oauth is just awesome.

We don't need to store people login and password, and make them remember another login and password. This means:

• User data is almost useless, the only important thing is the e-mail (a way to contact the person)
• Speaker data is really important

So, the user table does not means much to us, but the speaker table means a lot! The Facebook connect API should be used only for authentication purpose.
What this features should enable:

• User registration would make possible just by linking a new user to a facebook account
• A current existing user could link his account to an facebook account
• The login could be made by its current form, or by being logged into facebook
• Gather pre-data such as name, country, etc from his Facebook account