access rights: don't let a guest upload or delete a tradition nor edit a collation; rights depending on user/admin/guest

[schiwaa]

Upload Tradition, Edit Collation, Delete Tradition
a guest should never be allowed,
a user should be allowed for his own traditions,
an admin should be allowed for any tradition.

(#155: A guest should only see the public traditions listed on the dashboard.
OK already: Examine Stemma, Download Tradition, Download Stemma: guest, user and admin have the right to.)