update canonical links to remove '.html'

no need to specify it's a static resource
create demo link in documentation
temporarily hide internationalization content

there was an error when attempting to link to the chinese and hebrew
characters. need to debug the problem.
fix whitespace
tweak CSS to improve readability

- darken background
- increase font size
darken <hr> element
re-enable internationalization content

also: update top-of-page demo link

To re-enable the international content, we had to update the database
instance to support UTF8. For simplicity, we just cleared the old data,
creating new entries.