Improve Command-Line Processing

[michael-hawker]

I've got a fix to submit to add a -o outputfile as an option vs. dumping to console.
I think we should also allow providing a custom date -d date as an option vs. trying to automatically grab the last release (there may not be one if it's new, or may not align to other fixes).

For this we should probably use an actual helper for processing complex command-line option arrangements. 😊