Synnefo

Pithos frontend restricts public object listing only to the container owners.
Apply this control in the backend.

Also, review the backend implementation
to ensure that fits to the updated requirements for public behavior.

For example, the backend method _can_read() used to check
whether the user has read or public permission to the specific path
(http://www.synnefo.org/docs/synnefo/latest/pithos.html#pithos-back-end-permissions)
This should change to check only whether the user has read permission.