Update scrollspy.js

Scrollspy target in tab content does not work properly. Calling .parents('.active') will return all parents with an active class (including the tab pane). Changing this line to .parentsUntil(this.options.target, '.active') should resolve the issue. This will scope the query to only search for active elements inside the scrollspy target.
Added unit test for removing only active class from within the scroll spy key.
Fix: IE10 or lower incorrectly determines the scrollheight of the body. Use document.documentElement for IE. To make this browser agnostic, the maximum scrollheight of both body and documentElement is used.
Fix: IE10 or lower incorrectly determines the scrollheight of the body. Use document.documentElement for IE. To make this browser agnostic, the maximum scrollheight of both body and documentElement is used.
add .sr-only-focusable; fixes #12259
update docs to include+use .sr-only-focusable
replace .visible-{size} with .visible-{size}-{display} ; fixes #8869
Fixed flickering and simplified calculations

- Removed offending line causing a flicker to the default top state
- Simplified calculation of the top offset when in the bottom state
Add transition-timing-function mixin to docs
Do csscomb earlier in build phase
Reorganize docs assets
Merge pull request #12961 from BBosman/csscomb

Do csscomb earlier in build phase
Merge pull request #12505 from ZDroid/js-cs-hint

Reorganize docs assets
Move license to the top of the file.
Improve badges mixinability
rm #1969 from browser bugs list per outcome of investigation
Remove ./ from package.json paths
Remove ./ from _config.yml paths
Merge pull request #12971 from ZDroid/config-yml

Remove ./ from _config.yml paths
Merge pull request #12970 from ZDroid/package.json-pa

Remove ./ from package.json paths