Add switch to add Nothing selected to the countires array.
Add switch to add Nothing selected to the countires array.

If $addNothingSelected is set to true on
BTBookingCountries::get_countries(), an empty key with value 'Nothing
selected' will be added to the returned countries array.

Buschtrommel/BTBooking,Buschtrommel/BTBooking,Buschtrommel/BTBooking