IPA API: set krbcanonicalname instead of ipakrbprincipalalias on new entities
    
    Hosts, services, and (stage)-users will now have krbcanonicalname attribute
    set to the same value as krbprincipalname on creation. Moreover, new services
    will not have ipakrbprincipalalias set anymore.
    
    Part of https://fedorahosted.org/freeipa/ticket/3864
    
    Reviewed-By: David Kupka <dkupka@redhat.com>
    Reviewed-By: Simo Sorce <ssorce@redhat.com>