process the range of country labels which appear as columnar list from the
"ifconfig DEV list countries" command. Not only improving maintainability,
but also properly encapsulating arguments in single-quotes instead of
trying to escape whitespace. It is also completely unnecessary to collapse
newlines into whitespace (shell will do this for you automatically upon
expansion of the contents where necessary).
NB: This also changes the sorting algorithm to sort on the country code,
not the country name. The type-ahead feature of dialog is destroyed if the
tags are not sorted properly.