Polish ipa config help
    
    Remove config-mod options help from config module help to keep the
    option doc on one place and without unnecessary redundancy. The new
    format is more consistent with the rest of the plugins. Also fix
    several inconsistencies in the labels/doc, including:
    - using abbreviation when not needed
    - using '.' at the end of options help
    
    https://fedorahosted.org/freeipa/ticket/1906