Only enable `pause: hover` for non-touch browsers

Fixes #11967.
Fix #12563: Reiterate that empty tooltips+popovers do not get displayed
Merge pull request #14716 from blankmaker/docs/fix-12563

Fix #12563: Elaborate that popover('show') checks title/content
Merge pull request #14626 from twbs/carousel-pause-hover-non-mobile

Only enable `pause: hover` for non-touch browsers
fixes #14714: don't use specific value in buttons docs
Merge branch 'master' of github.com:twbs/bootstrap
grunt
Escape key should only close Dropdown
Fixes #14711: Account for list groups in collapsing panels
Merge branch 'master' of github.com:twbs/bootstrap

Conflicts:
	docs/assets/js/raw-files.min.js
more grunt
Merge pull request #14722 from twbs/fat-14646

Escape key should only close Dropdown
fix #14254  Modal Sometimes Does Not Appear after Multiple Displays in Safari
Merge pull request #14723 from twbs/fat-fix-14254

fix #14254  Modal Sometimes Does Not Appear after Multiple Displays in S...
Fixes #14251: Don't use hidden screen reader content in docs table so that Safari doesn't screw up overflow: hidden; content
Merge branch 'master' of github.com:twbs/bootstrap
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