Changed links for gist comments to link straight to the comment section.
Started on a cleanup of the existing commit-based code.
Added a test skeleton.
Fixed line width where it still made sense.
Fixed error display when the mappings file is unavailable.
Updated the ancient async.js dependency.
Moved from hide/show to class based visibility for error handling and click handlers.
Updated the tests with sinon and chai.
Added minor readability improvement.
Added two initial tests.