fixes #12211: Scrollspy: Navs in different tabs can interfere with each ...

pending the release of v3.2.0's updated hosted docs.

Fixes #13572.

IE8 button group support

Fixed affix-bottom positioning

commit 81324491f4913d6797c3c9e4df83a1aefd7d9116
Author: Daniel <dano.husar@gmail.com>
Date:   Sat May 10 17:37:29 2014 +0100

    use opacity mixin

commit 694b0a3fcd196e8cba9e4c23850f903c0804cb44
Author: Daniel Husar <dano.husar@gmail.com>
Date:   Fri May 9 13:47:35 2014 +0100

    Update button-groups.less

add some ARIA roles to tabs for improved accessibility

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

Per https://github.com/paypal/bootstrap-accessibility-plugin#tab-panel
Credit: https://github.com/paypal/bootstrap-accessibility-plugin

Per https://github.com/paypal/bootstrap-accessibility-plugin#tab-panel
Credit: https://github.com/paypal/bootstrap-accessibility-plugin

Customizer: make utilities.less inclusion mandatory

Fixes #13305.

Set top position to (scrollHeight - this.$element.height() - offsetBottom).

Remove outdated rtl nav links

move Grunt info from README into HTML docs

Fixes #13470

emphasize that bootstrap-rtl.css & bootstrap.css should not be used together

Fix .visible-print deprecation version #.

unlock & bump grunt-jscs-checker to ~0.4.3

Allow for resetText of a button to be a falsey value; fixes #13466

fires closed.bs.alert *after* DOM detach() as per #12379

bump grunt-jscs-checker to v0.4.1

Per #13512 & https://github.com/mdevils/node-jscs/issues/357

import rules from Ratchet's JSCS config with which we already comply