Implemented proper help output.
Implemented proper help output.

Implemented --help option to produce useful output. In the process
I cleaned up some option specifications, and improved determination
of some default values.

tzz/design-center,bdurrow/design-center,bdurrow/design-center,tzz/design-center,bdurrow/design-center,bdurrow/design-center,tzz/design-center,tzz/design-center