don't show tooltips/popovers whose element isn't in the DOM; fixes #13268
Merge pull request #13752 from twbs/fix-13268

Proposed fix for #13268
there is no need for this.offsets and this.targets to be jQuery objects
no need to check for href attribute on the scrollable element
removing this.$element as it is a superfluous copy of this.$scrollElement
refactor scrollspy refresh method

Closes #13702 by merging a rebased version of it.
Merge branch 'mikegreiling-scrollspy-update'
Adds isolated visual tests for javascript plugins (decoupled from docs). This makes it
faster and easier to test/develop js functionality not represented in unit tests, and gives us
a playground for interactions, etc.

It also makes it so developing javascript is now decoupled form jekyll, which should make everything
faster and less painful.

This commit also reverts my filter commit https://github.com/twbs/bootstrap/commit/9900771aa7f1b3ddcee49aec84082104776ace70
which broke scrollspy for dropdowns.
Merge pull request #13744 from twbs/fix-13650

replace SemVer summary with a link to its website
fixes #13210: clean up tooltip example
Merge pull request #13745 from twbs/fix-13281

set not-allowed cursor on disabled radio+checkbox labels
Merge pull request #13649 from ItsJonQ/repaint-fixes-2

Repaint Fixes When Scrolling
grunt
grunt
Merge pull request #13542 from twbs/icon_paths

Fixes #13478, reverts #10941
fix nested containers (addresses some of #13682)
Merge branch 'master' of github.com:twbs/bootstrap
Merge pull request #13735 from skhilko/master

Fix bug where a panel recieve extra top border when placed within a collapsible panel
grunt
Merge branch 'master' into pr/13736

Conflicts:
	dist/css/bootstrap.css.map
	dist/css/bootstrap.min.css