WebKit CSS3 carousel transforms for supported devices
Utilised mixins rather than specific WebKit properties
Removed unnecessary percentage sign for 3D translation
Improved mixin ability with nested media query
Add aria-haspopup and aria-expanded attributes to dropdown plugin

1. Add aria-haspopup="true" and aria-expanded="false" to dropdown docs
2. Toggle aria-expanded between "true" and "false" when opening and closing dropdown

Satisfy item 1 from https://github.com/paypal/bootstrap-accessibility-plugin#dropdown. See #13553.
allow require.resolve('bootstrap') to work under node
added 'main' field to package.json
Ensure that hidden event is sent when content is really hidden (collapsing class is removed)
Added Firefox support for CSS3 carousel transition
Expose transition durations on plugin constructors; closes #13656
CSS3 Carousel code formatting
popover dismiss-on-next-click example: instead of <button>, use <a> w/ tabindex

Fixes #14038.

Research supporting this choice of approach:
    https://gist.github.com/cvrebert/68659d0333a578d75372

Why not <button>?
Even with a `tabindex` attribute, they don't gain focus when clicked upon in:
    * Mac OS X Firefox 30.0
    * Mac OS X Safari 7.0.5
regenerate docs/assets/js/docs.min.js
Clean up Affix documentation
Clean up the Alert documentation
Merge alert examples and add `.bs-example-standalone` class
Add a bottom affixed element to affix visual tests.
Refactor determining affix state into a separate expanded method
  in order to handle multiple edge cases, specifically when the document
  height is dynamic.
Always reposition an affix that is affixed to the bottom.
Fix issue where bottom affixed element floats over the footer when the
  document height is smaller than the viewport height.
Document limitations of buttons JS plugin

Addresses #14148.