Ticket 47840 - default instance scripts if undefined.
    
    Bug Description:  During the change, 47840, per instance scripts defaulted
    to false if not defined in setup.inf.
    
    Fix Description:  reset the default to true, and allow setting to false if
    required. This may change in a future release.
    
    https://fedorahosted.org/389/ticket/47840
    
    Author: wibrown
    
    Review by: One line commit rule.