Remove `.modal-open` class after backdrop is hidden

Fixes #14274.
Fixes #14632.
Remove Safari percent rounding bug entry from Wall of browser bugs

Bug is fixed in OS X Safari v7.1
Refs #14663
Remove #8702 entry from Wall of browser bugs

A fix is shipping in Firefox 35: https://bugzilla.mozilla.org/show_bug.cgi?id=763671
Merge pull request #14570 from twbs/remove-modal-open-after-backdrop-closed

Remove `.modal-open` class after backdrop is hidden
grunt
document S3Cachefile.json
Safari percentages were fixed in v7.1 & iOS 8.0; fixes #14663
Merge pull request #14666 from twbs/fix-14663

Update docs to reflect that Safari percentages were fixed in v7.1 & iOS 8.0
Fixes #14227, #14603: Drop translate3d for translate on navbars to avoid iOS rendering problems and ensure a more predictable base styling
Merge branch 'master' into remove_translate3d
grunt
Merge pull request #14667 from twbs/remove_translate3d

Remove translate3d
fixes #14654: callout for scrollspy-nav link
Reverts 0ec05da0eea03849fc72bed84a2c7fe7be1de1b6 to bring back #14444 to fix #14348 (again)
Add brief note about justified navs being unsupported to fix #14598
Document that the autofocus attribute doesn't work in modals.

Closes #14478.
Mention HTML5 validator and Bootlint as part of troubleshooting steps

Fixes https://github.com/twbs/bootlint/issues/67
linkify reference to Nav component in Scrollspy docs
Also mention the "no justified navbars" limitation in the Nav docs

Refs #14598
[skip sauce]
Mention Bootlint in Getting Started docs under new Tools section

[skip sauce]