Unite and move facet pre_ops to related modules
    
    Facet pre_ops defined in ./facet module were moved to modules where facet are actually defined. Moved pre_ops were united with the ones defined for the facets in these modules.
    
    The move simplifies module dependencies - there is no reason to have general facet module dependent on specialized facet modules.
    
    Pre_ops uniting makes the code simpler.
    
    https://fedorahosted.org/freeipa/ticket/3605