Warn user about realm-domain mismatch in install scripts
    
    If the IPA server is setup with non-matching domain and realm
    names, it will not be able to estabilish trust with the Active
    Directory.
    
    Adds warnings to the ipa-server-install and warning to the
    ipa-adtrust-install (which has to be confirmed).
    
    Man pages for the ipa-server-install and ipa-adtrust-install were
    updated with the relevant notes.
    
    https://fedorahosted.org/freeipa/ticket/3924