Add per-SP attribute mapping and allowed attributes
    
    The per-SP values are considered overrides and the global values
    are default.
    
    https://fedorahosted.org/ipsilon/ticket/25
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-by: Simo Sorce <simo@redhat.com>