Allow clearing to load from closest A not parent

Currently clearing loads images from the current item if it's an `a` tag or from the parent of the current item or failing that it falls back to the item it's self. This means that the only way to load an image from the `a` tag is if the `img` tag is the direct descendant. By changing to use `closest('a')` instead of `parent()` then we gain more flexibility in the HTML we can use.
Rectify styles being cached permanently in issue 5827
Incorrect pseudo-element being referenced in dropdown button styling
Fix range slider with label
Fixes #3848: makes modal bg show/hide when swap style.

If one modal step is followed by a default style step, modal background
is hidden and if a default style step is followed by a modal step, the
modal background is shown.
Avoid to show joyride modal before needed.

This way, is up to the settings how the joyride modal will be shown
(with a simple show method or a fade effect).
Use fadeOut to hide joyride modal bg according to settings.
Active state styling

Actually makes use of the $icon-bar-active-color variable to set the
background when an "active" class is added to the anchor, akin to what
happens with the :hover pseudoclass.
Add x-only named media queries with documentation
Fix doc formatting
Fix code formatting
Update foundation.clearing.js
Update foundation.dropdown.js
Update foundation.joyride.js
Update foundation.js
Update foundation.magellan.js
Update foundation.offcanvas.js
Update foundation.orbit.js
Update foundation.tab.js
Update foundation.topbar.js