Provide theme setting for picking local bootstrap or hotlink from bootstrap CDN

http://www.bootstrapcdn.com/ provides free Bootstrap hosting. This would be extremely valuable for Drupal distros that cannot package Bootstrap as part of the download due to licensing issues (detailed here: https://github.com/twitter/bootstrap/issues/2054) and would allow some users to skip a step.

This should be fairly easy to do:

function hook_preprocess_page(&$vars) {
  // Check for https and set $protocol to either 'http' or 'https'
  drupal_add_js($protocol . '://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.1/js/bootstrap.min.js', 'external');
  drupal_add_css($protocol . '://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.1/css/bootstrap-combined.min.css', 'external');
}

Wrap that with a conditional for the theme setting and you're all set.