consolidate relatedTarget docs in dropdown event docs
Don't line wrap event names in JS plugin docs
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
Move context-specific callout to general tag usage
Move button-tags section to start of button section
upgrade OS X tests to Yosemite

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Merge pull request #15149 from twbs/yosemite

upgrade OS X tests to Yosemite
upgrade iOS tests to 8.1

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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>
Merge pull request #15129 from twbs/examples-img-alt

Specify `img` alternative text.
Merge pull request #15152 from twbs/fix-15144

honor wrap option in Carousel.getItemForDirection
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