Improve error handling and return status codes in ipactl
    
    There are cases when ipactl returns success even when it fails. Plus,
    when the error really is detected the status codes are not LSB
    compliant. This may result in consequent issues.
    
    This patch improves error handling in ipactl and adds LSB compliant
    status codes. Namely:
    
    0   program is running or service is OK
    3   program is not running
    4   program or service status is unknown
    
    for "status" action. Status code 4 is issued when IPA is not
    configured to distinguish this state from not running IPA.
    
    For other actions, the following non-zero status codes are
    implemented:
    
    1   generic or unspecified error
    2   invalid or excess argument(s)
    4   user had insufficient privilege
    6   program is not configured
    
    https://fedorahosted.org/freeipa/ticket/1055