Enable localization of the copyright page

Enable localization of the copyright page

The copyright page introduced in ecbd526 wasn't localize-able. Rectify
that with a page that:

   * Displays a header in non-English languages indicating that the
     version you're looking at isn't canonical.

   * Links back to the local version from the English one in a
     non-English locale.

Additionally I fixed a regression with the cc_button.png. It now has a
meaningful alt="" text again.