Introduce ipa control script that reads configuration off ldap
    
    This replace the former ipactl script, as well as replace the current way ipa
    components are started.
    
    Instead of enabling each service in the system init scripts, enable only the
    ipa script, and then let it start all components based on the configuration
    read from the LDAP tree.
    
    resolves: https://fedorahosted.org/freeipa/ticket/294