Cs.auth.facebook

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- Fix docs
[erral]

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- Fix user search
[erral]

- Fix to be able to add the plugin through the ZMI
[erral]

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- FaceBook users are now PloneUsers
[erral]

- Implement user search in storage
[erral]

- Get properties from self data storage instead of relying on Session
[erral]

- Change user action name not to clash with Plone's login
[erral]

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- Initial release
[erral]