Fixes #13098
Closes #13099

Closes #12850

Closes #12377

closes #12337

Fixes #13003: Move padding on radio and checkbox options from the surrounding div to the label to remove the no-click deadzone caused by negative margin

Move all deprecated vendor prefix mixins to less/mixins/vendor-prefixes.less
Create mixins directory and move partials to that directory.

FIXES #12994

Ensures proper sizing and alignment of input groups within inline and
navbar forms.

* Uses `inline-table` on the input group
* Nukes the widths to `width: auto`—without this, the parent input
group doesn’t size correctly and functions as `display: table;` or
`block`

* Removes default max-height from .navbar-collapse (so not every navbar
will get a max-height collapse section)
* Scopes regular 340px max-height to fixed top and bottom navbars only
(those are the only ones that really need a max-height to enable
scrolling)
* Adds a landscape media query for phones to cap the max-height at
200px for fixed navbars"

Fixes #12843: Scope label styles for horizontal forms to a media query so their narrow viewport display looks just like a normal form

Fixes #12669: Properly reset line-height on date inputs for all sizes; Fix IE8+'s misaslignment of text within date inputs

FIXES #12992

Moving the embed to it's own CSS file, moving the docs to the Components page with an example, fixing a Glyhpicons list problem in the docs

Fixes #12683: Remove the overflow: hidden; from the .panel-group > .panel because it apparently serves no purpose and cuts off nested dropdown menus.

Safari renders this fine for one reason or another, but Chrome still renders the media query styles to make tables responsive. This change scopes them to screen devices only, so printing looks boss everywhere.