Move old stuff to old/.

My pea-sized brain can't manage two code bases in the same space.
Moved old stuff to old/. Copied over and customized just what we
have working. I did not recreate the directory structure we had
before. It was confusing to know what is done and what needs work.
Instead, I would like to see us grow the directory structure. Only
put in place and keep what is working and useful. The less we have
to look through, the better.

New conventions for files in bin/
  * All files will start with mt- (for mousetrap).
  * Executables are to be ran as normal.
  * Non-executables are to be sourced as needed.

Now when you sit down to work you might do something like

  source bin/mt-setup   # adjusts paths and defines variables
  mt-test               # run tests
  mt-install            # build and install mousetrap

No runner exists yet because we don't have an entry point yet.

Need a pylint runner (mt-pylint).