#113 User can delete himself

This implementation doesn't cover the use case where the theme is changed for the page.  The overriding theme may not do the same exclusion on the client side.  

Would be best to modify the query above to exclude the user's ID in the where clause:
```
var where = pb.DAO.getNotIDField(self.session.authentication.user_id);
where.admin = {$lte: self.session.authentication.user.admin};
dao.query('user', where).then(function(users) {
     ...
});
```