Ticket 49 - pkgconfig missing -L option
    
    Bug Description:  pkgconfig for nunc-stans is missing -L, which hinders use
    in an alternate prefix
    
    Fix Description:  Add -L option
    
    https://fedorahosted.org/nunc-stans/ticket/49
    
    Author: wibrown
    
    Review by: mreynolds (Thanks)