morse(6): implement support for decoding morse code

• Use -r for "reverse" mode and to match DragonFlyBSD.
• Move defines around to clear up logic
• use errx instead of fprintf and exit

PR: 35109
Submitted By: philipp.mergenthaler@stud.uni-karlsruhe.de
Submitted on: 2002-02-19
Reviewed by: kevans