Specify `img` alternative text.
Expand caveat for disabled fieldsets and links
Redundant role="form" on <form>s
Redundant role="navigation" on <nav>s

plus one example that still used the old <div role="navigation"> and a
fix-up of the callout as per
https://github.com/twbs/bootstrap/issues/15109
Collapse: Use $.fn.children instead of `>` in selector

Fixes #15131.
split .form-inline .input-group into separate docs example
Filed http://openradar.appspot.com/18987206

Refs #9774
Merge pull request #15137 from twbs/split-inline-form

split .form-inline .input-group into separate docs example
[skip sauce]
Move context-specific callout to general tag usage
Move button-tags section to start of button section
upgrade OS X tests to Yosemite

[skip validator]
Merge pull request #15149 from twbs/yosemite

upgrade OS X tests to Yosemite
upgrade iOS tests to 8.1

[skip validator]
Merge pull request #15150 from twbs/ios-8.1

upgrade iOS tests to 8.1
add unit tests for Carousel's 'wrap' option
honor wrap option in Carousel.getItemForDirection; fixes #15144
Add modal autofocus example
Merge pull request #15135 from hillai/patch-1

Add modal autofocus example
Merge pull request #15139 from patrickhlauke/docs-button-section-restructure

Docs button section restructure
rm redundant role="button" from <button>