initial work towards native 8-bit storage

[jywarren]

This is incomplete, but a stubbing out of basic features described in #18.

• tests pass -- see README.md for how to run them
• code is in uniquely-named feature branch, and has been rebased on top of latest master (especially if you've been asked to make additional changes)
• pull request are descriptively named
• if possible, multiple commits squashed if they're smaller changes
• reviewed/confirmed/tested by another contributor or maintainer

[jywarren]

Just a note that I'm renaming the master branch to main and this will have to be merged into main as well.