bug 1077879 - Improve view_feature HTML view

- Whenever support changes between versions, add it to
  meta.compat_table.supports (for example, supported with prefix to
  supported without prefix)
- In meta.compat_table.supports, order features by tree order, not hash
  order
- Add meta.compat_table.footnotes - Important supports with footnotes
- Add notes, footnotes, and prefixes to HTML view
- If support is not "yes", display next to version number
- Plain support "yes" displayed in parens: "(yes)"