add responsive CSS to hyperlinked images when thumbnail caption markup is used

When thumbnail caption markup is used in combination with a hyperlinked image, the image is not responsive. (non-hyperlinked images are fine, like the example in the docs) Adding a selector to apply responsiveness to hyperlinked images when thumbnail captions are used.
Adding contextual styles to list-items
Active state overrides contextual list-item styles
replace double quotation marks with single in code examples
Merge pull request #11667 from neilhem/master

replace double quotation marks with single in code examples
Merge pull request #10662 from kevinlisota/thumbnail-images

add responsive CSS to hyperlinked images when thumbnail caption markup used
Update holder.js to v2.2.
Update jszip.js to the latest git.
Update filesaver.js to the latest git.
Added text-justify class to type.less
Get rid of empty line before the last closing bracket
Merge pull request #11690 from lipis/patch-2

Get rid of empty line before the last closing bracket
Gruntfile.js: Set line feed char to '\n' to get same result on all platforms.
add .gitattributes file to enforce Unix newlines within the repo
reference root issue in explanatory comment
account for #11050 in the docs
Merge pull request #11691 from twbs/xs-grid-docs-fix

document that XS grid supports offsets and push/pull
add comment regarding #11598
grunt
add <table> case to responsive-visibility mixin; see #10056