make LuisDialog more amenable to inheritance
make LuisDialog more amenable to inheritance

digibaraka/BotBuilder,yakumo/BotBuilder,dr-em/BotBuilder,msft-shahins/BotBuilder,stevengum97/BotBuilder,msft-shahins/BotBuilder,jockorob/BotBuilder,navaei/BotBuilder,yakumo/BotBuilder,digibaraka/BotBuilder,xiangyan99/BotBuilder,stevengum97/BotBuilder,xiangyan99/BotBuilder,Clairety/ConnectMe,stevengum97/BotBuilder,navaei/BotBuilder,dr-em/BotBuilder,jockorob/BotBuilder,mmatkow/BotBuilder,msft-shahins/BotBuilder,stevengum97/BotBuilder,Clairety/ConnectMe,mmatkow/BotBuilder,xiangyan99/BotBuilder,Clairety/ConnectMe,jockorob/BotBuilder,digibaraka/BotBuilder,dr-em/BotBuilder,mmatkow/BotBuilder,Clairety/ConnectMe,yakumo/BotBuilder,msft-shahins/BotBuilder,digibaraka/BotBuilder,navaei/BotBuilder,navaei/BotBuilder,yakumo/BotBuilder,xiangyan99/BotBuilder,dr-em/BotBuilder,mmatkow/BotBuilder,jockorob/BotBuilder