Correctly handle SIGINT during countdown

During the configuration and retag countdown functions, correctly
display title messages and cleanly exit.

__trap_sigint():
  Add the additional 'countdown' parameter to correctly handle various
  items printed to STDOUT.

  Merge in __exit_cleanup(), making one unified trap/cleanup function.
  Since we no longer have the option of using two parameters with this
  function, we can cleanly remove the $post_row variable and use literal
  newlines, simplifying where to print messages.

__exit_cleanup():
  Removed this function as its functionality was merged into
  __trap_sigint().

Miscellaneous:
  Removed superfluous cursor placement after an operation completed.