This is a cleanup of the rb-site and prepare-dev.py code, moving

away from the page and callback-based ConsoleUI code we've used for

years and to the new, more general Console code.
For the most part, the presentation remains the same, with a few

differences:


The text is no longer indented 2 spaces in the UI, creating a more

  consistent look with other commands.


Some of the sections were given better/updated instructions.


Upgrade code now uses sections and progress steps for the operations,

  improving the presentation.

Unit tests pass.
Made a note of every single string in rb-site and prepare-dev.py

(by adding XXX TEST comments). Walked through every variation of

both scripts, checking each set of strings and marking it off the list.

This included optional steps and errors. Verified every string looked

the way I expected it to, and executed properly.