bug 1077879 - Add JS-enabled HTML generator

/view_feature/<feature_id> will call /api/v1/view_features/<feature_id>
and display the available data.  It resembles the MDN format, but is not
supposed to be identical.
bug 1077879 - Add link to browse app

On the browse detail page /browse/features/<feature_id> , add a
prominent link to the JS-enabled feature view
fix bug 1077879 - Add upload of features.sections

Move features.sections to the writable links section, so that they are
considered significant when tools/upload_data.py looks for changes.
Also used OrderDict when loading the local data collection, so that
translations will be correctly ordered and diffs will be easier to read.