#55 Import Export of user/profile/permissions

[Luca Garulli]

The USERS Module need to Import/Export all users,
profiles and permissions in a XML file.

In this way users can easy migrate long profiling
setting across installations and, why not, different
version of own application.

Any volounteer? I'd like to use XML because is easy to
write by cruise the Object DOM and to parse it you can
choose tens of implementations ;-)

Cool!