Docs audit prompted by #13697.
[skip sauce]

The validator doesn't choke anymore on this and even though it's not spec compliant, it's needed for some IE versions. So until we move favicon.ico in root, this should do the job.

Per https://github.com/paypal/bootstrap-accessibility-plugin/blob/master/README.md#carousel
Credit: https://github.com/paypal/bootstrap-accessibility-plugin

Closes #13379.

Also, use Google's CDN per #11369.

Replaces links to holder.js with links to the new docs.min.js.
The uncompressed holder.js file is now in docs/assets/js/vendor,
which is excluded from Jekyll builds. In turn, Holder is now
included in docs.min.js, which is smaller than holder.js,
so this should make everybody happy. :)

- Implements new format "Copyright 2011-xxxx Twitter, Inc.", which resonates well with our History page and more accurately reflects the copyright status of the repo
- grunt dist to update all the files

As per the docs:
http://getbootstrap.com/components/#navbar-default

  modified:   examples/carousel/index.html
  modified:   examples/jumbotron/index.html
  modified:   examples/navbar-fixed-top/index.html
  modified:   examples/navbar-static-top/index.html
  modified:   examples/navbar/index.html
  modified:   examples/non-responsive/index.html
  modified:   examples/starter-template/index.html
  modified:   examples/sticky-footer-navbar/index.html
  modified:   examples/theme/index.html

- works when viewing page via file://
- sets a good example security-wise

...because we don't support it and it may cause problems for people
trying to view the docs in IE.

Missed the <a class="btw" in my regex search