v0.12.0-v0.12.1 breaks paths in URL.

Bump devDependencies.

Fixes #15653 — Add comment which explains that how a responsive im...

Fixes #15653 — Add comment which explains that how a responsive image should be centered

Redo of #15657 which I couldn't get to rebase properly after all the merges were done last night.

[Fix Issue #15682] .caret is smaller in Firefox than other browsers

Improve image layout in the carousel example.

[Fix Issue #15719] Add a variable for .form-group's margin-bottom

Update Twitter handle: @twbootstrap => @getbootstrap

Refs https://github.com/twbs/bootstrap-blog/commit/1c94b7791f8a24a18f08aba40c38d519b873f2d0
CC: @mdo

Skip link workarounds for Chrome and IE

[Fix Issue #15701] [Docs] Tooltip/popover destroy docs and delegation

[Fix Issue #15701] Tooltip/popover destroy docs don't explain the delegation case.

Add to popovers

Clarify target of carousel events

Clarify target of modal events

[skip sauce]

Fix issue #15601 — Position of Charset, X-UA-Compatible, and Viewport Meta Tags

Extract responsive embed nested classes

Fix issue #15601 — Position of X-UA-Compatible, charset and viewport

Add comment to all examples

The non-responsive is correctly saying 2 instead of 3

Use local HTML validator to improve performance

[Fix issue #15719] Add a variable for .form-group's margin-bottom

I think this is the more common coding convention across Bootstrap.

Extract nested classes as first-class citizens and assume HTML would use both.

Update customizer libs

Add tabindex="-1" to main #content to work around bug in Chrome (and old
WebKits) and IE
Update advice in accessibility section
Include patch in docs CSS to suppress outline when #content is focused
(particularly as Chrome sets focus as result of mouse click for
tabindex="-1" elements)

License FAQ clarification