Add attributeTypes to safe schema updater
    
    AttributeType updates are sensitive to case, whitespace or X-ORIGIN mismatch
    just like ObjectClass attribute which is already being normalized before
    an update value is compared with update instructions.
    
    Expand safe schema updater routine to cover both ObjectClasses and
    AttributeTypes updates.
    
    https://fedorahosted.org/freeipa/ticket/2440