Apply @color argument to striped gradient

The @color argument is currently not being used for the striped gradient.
Remove progress bar striped @color parameters; use default transparent white.

* If the @color parameter is not removed, the stripes are the same color as the element background color. In this case, the stripes do not appear.
Fixing carousel control positioning

The left control should be positioned from the left, while the right
control should be positioning from the right. Positioning both from the
left results in the right carousel control being incorrectly positioned
(most noticeable with a larger than normal font size).
Add missing methods (rotateX/Y, perspective(-origin) and transform-origin)

Added missing mixins:
rotateX
rotateY
perspective
perspective-origin
transform-origin
Deprecate container-{device} vars for container-{size} classes; updates customizer and grid to do the same
correct enable selector for button usage

following the given examples the correct selector to enable the buttons with javascript is ".btn-group".
Add missing period on customize page.
Merge pull request #10204 from premist/master

Add missing period on customize page.
[doc] tweaked the appearance of the last item of the file listings
Fixes #10207: alert-dismissable example requires contextual class
per the docs - use <a> instead of <button>
add  role="button"
Compress PNG files losslessly.

Use zopfli with 1000 iterations, pngout /r with various blocksizes and deflopt.

assets/ico/apple-touch-icon-114-precomposed.png | Bin 2939 -> 2931 bytes
assets/ico/apple-touch-icon-144-precomposed.png | Bin 3614 -> 3549 bytes
assets/ico/apple-touch-icon-57-precomposed.png  | Bin 1577 -> 1573 bytes
assets/ico/favicon.png                          | Bin 889 -> 887 bytes

Total difference: -79 bytes.
Update Respond.js to v1.3.0.
Update html5shiv.js to v3.6.2.
Add bugs property to package.json.
Merge pull request #10210 from acmetech/master

Update the example for components/#btn-groups-justified to match the "Element-specific usage" callout
Merge pull request #10209 from clbn/master

Fixes #10207: alert-dismissable example requires contextual class
Merge pull request #10208 from javiereguiluz/patch-2

[doc] tweaked the appearance of the last item of the file listings
Merge pull request #10215 from XhmikosR/master

Various