Openstack project list should use V3 unscoped token to get list of projects when a user doesn't have the admin privileges

[Elancheran S]

When only admin_or_owner is allowed to list_projects in keystone, the other user who are not `ProjectAdmin` or `Member` won't be able to see the list of project they have access to.

So when there is a 403 for `openstack project list` openstack client should revert back to use the unscoped token along with user filter to get the list of projects a user has access to when the user uses the `--os-identity-api-version 3`

http://developer.openstack.org/api-ref/identity/v3/?expanded=password-authentication-with-unscoped-authorization-detail