** Bugfix: Fix PIV feature detection for some YubiKey NEO versions.
** Bugfix: Fix argument short form for --period when adding TOTP credentials.
** Bugfix: More strict validation for some arguments, resulting in better error messages.
** Bugfix: Correctly handle TOTP credentials using period != 30 AND touch_required.
** Bugfix: Fix prompting for access code in the otp settings command (now uses "-A -").