Fix accordion behavior with JQuery interface

Carousel - Add attributes from and to for Slid and Slide events

* Allow to use Tab.js with list-group

* Allow to use list-group with div parent instead of an ul parent

Closes https://github.com/twbs/bootstrap/issues/21635

* Close dropdown menu when focusing an outside element
* Update unit test to new markup

* Remove IE compatibility mode meta tag from docs, examples, and JS tests as we no longer support IE9 and IE8
* update and remove some IE bits from our supported browser page
* update introduction.md to match
* reword starter template intro

* [Fix #19849] Tabs are opened even if disabled.

* fix hund code review hints

* rollback hound issues because Travis fails

Fixes 2 bugs:

1. All keydowns were being prevented. Because of that the user wasn't able to navigate in the whole page using ARROW_UP/ARROW_DOWN.

2. Even when  is an input or textarea the keydowns were being prevented. Because of that the user wasn't able to type any text on these elements.

* Throw error when a plugin is in transition
* Add unit tests about plugins in transition

When the rubberband effect causes Safari to scroll past the top of the
page, the value of scrollTop becomes negative. If the offset of the first
ScrollSpy target is 0 - essentially if the target is at the top of the
page - then ScrollSpy should not clear the active item. Conceptually, the
first item should remain active when rubberbanding past the top of the
page.

This commit fixes issue #21055 by verifying the first scrollspy target is
not at the top of the page before clearing the active nav-item.

* Fix bug with dropdown tab links not deactivating when other tab or dropdown link is clicked

* Revise bug fix for more stability