Improve hostname verification in install tools
    
    Our install tools like ipa-server-install, ipa-replica-{prepare,
    install} may allow hostnames that do not match the requirements
    in ipalib. This creates a disconnect and may cause issues when
    user cannot delete hostnames created by install tools.
    
    This patch makes sure that ipalib requirements are applied to
    install tools hostnames as well.
    
    https://fedorahosted.org/freeipa/ticket/2089