Actually wait for the collapsed item to complete. If complete is called
with other target, instead of simply returning and do nothing, wait again
until the proper target triggers the event (otherwise this leaves collapse
in a broken state).

Closes #11281 by merging it (after rebasing & resolving conflicts)

Addresses #13248.

Closes #13103 by merging it.

Closes #12850

Closes #12377

closes #12337

X-Ref: https://github.com/twbs/bootstrap/commit/8c9739d4773c268b114296d90e61b5f4e2932517

See https://github.com/paypal/bootstrap-accessibility-plugin/blob/master/README.md#tooltip

Can't disable it just for the Gruntfile due to https://github.com/mdevils/node-jscs/issues/287

- Removed offending line causing a flicker to the default top state
- Simplified calculation of the top offset when in the bottom state

- Improve comments.
- Remove `transition.js` script load as `transition.js` unit test doesn't exist.

Makes life for people with custom jQuery builds excluding event aliases much easier.