WebKit CSS3 carousel transforms for supported devices
Utilised mixins rather than specific WebKit properties
Removed unnecessary percentage sign for 3D translation
Fixed nested tab elements li activation

Added closest li instead of direct parent so that you can nest multiple elements within tabs, such as button groups
Add nested kbd element styles for actual keys or inputs
Dropdown menu in justified button-group

It seems that dropdown-menu in justified button-group appears at the far
left of the group. Check the problem in [Bootstrap
site](http://getbootstrap.com/components/#btn-groups-justified).
Improved mixin ability with nested media query
Changed last-child to first-child
As noted by @jerem the first child will actually be the last shown
replace js scrollspy test for default behavior
add button to toggle the optional theme when viewing the docs; fixes #9764
regenerate minified docs JS & CSS
Fixed affix-bottom positioning

Set top position to (scrollHeight - this.$element.height() - offsetBottom).
Fixes #13478, reverts #10941
grunt dist
Customizer: make utilities.less inclusion mandatory

Fixes #13305.
Merge pull request #13543 from twbs/fix-13305

Customizer: make utilities.less inclusion mandatory
add role="tablist" to .nav-tabs in examples to improve accessibility

Per https://github.com/paypal/bootstrap-accessibility-plugin#tab-panel
Credit: https://github.com/paypal/bootstrap-accessibility-plugin
add role="tab" to .nav-tabs [data-toggle="tab"]

Per https://github.com/paypal/bootstrap-accessibility-plugin#tab-panel
Credit: https://github.com/paypal/bootstrap-accessibility-plugin
add role="button" to [data-slide="prev"],[data-slide="next"] to improve accessibility

Per https://github.com/paypal/bootstrap-accessibility-plugin/blob/master/README.md#carousel
Credit: https://github.com/paypal/bootstrap-accessibility-plugin
Merge pull request #13559 from twbs/carousel-role

add role="button" to [data-slide="prev"],[data-slide="next"] to improve accessibility