Add Embed responsive utility
Merge branch 'responsive-embed' of https://github.com/boulox/bootstrap into boulox-responsive-embed

Conflicts:
	dist/css/bootstrap.css.map
	dist/css/bootstrap.min.css
Added .list-group-item.disabled

Added support for disabled List group item.
Update variables.less
Documents #10140
Merge branch 'master' into document_popover_focus
add posibillity to hover links and not background in list-groups
Fix UAs required message position on grouped radio buttons

Instead of not rendering the element at all with display:none, use opacity:0 and z-index:-1 so the radio element has a defined position on the document and user agents can show the required message in the right place.
Remove ./ from bower.json paths
Fixes #12934
Fixes #12722: Fixes up responsive tables in print

Safari renders this fine for one reason or another, but Chrome still renders the media query styles to make tables responsive. This change scopes them to screen devices only, so printing looks boss everywhere.
Merge branch 'master' of github.com:twbs/bootstrap
Merge branch 'master' into pr/12490

Conflicts:
	less/list-group.less
Rewrite the disabled list group items to simplify styles
Merge branch 'master' into popovers-use-radii-var

Conflicts:
	dist/css/bootstrap.css.map
	docs/assets/js/raw-files.min.js
	docs/dist/css/bootstrap.css.map
Fixes #12683: Remove the overflow: hidden; from the .panel-group > .panel because it apparently serves no purpose and cuts off nested dropdown menus.
Merge branch 'master' into boulox-responsive-embed

Conflicts:
	dist/css/bootstrap.css.map
	dist/css/bootstrap.min.css
	docs/assets/js/customize.min.js
	docs/assets/js/docs.min.js
	docs/css.html
	docs/dist/css/bootstrap.css.map
	docs/dist/css/bootstrap.min.css
Specify engines in package.json.

Things don't work with older versions.
Remove duplicate dependency.
Add time-grunt plugin.