Major upgrade.

TODO: Create more test cases, suites.  Figure out how to landmark the
“document” page.

STUFF DONE:

— New names [Left Panel => Folia Manager, Memo Screen => Folia Root].

— Matches the functionality of Folia [reduced a lot of the “goto” stuff.

— New images for new UI.

— Refactored some test cases, deleted some test cases.