* Instead of .divider-vertical, use .divider
* Makes use of .nav-divider mixin
* Dividers are horizontal to start, matching the default state of navbar nav links
* Dividers become vertical above 768px via media queries

this is a resubmission of #5875, but now against branch 3.0.0-wip
does not exclude elements under a fieldset's legend
issue #6058 is a duplicate of #5605

* Includes text inputs, selects, and textareas
* Updated docs to include .span* sizes wherever possible
* Commented out responsive 1200px inputs grid
* Still some derp to be done to improve more, but this is a decent first stab

Previously, we were using a generic label selector, but as this was changed in the main forms awhile back, we need to change it here.

remove -moz-box-shadow from .box-shadow() mixin, but keep -webkit since that's needed for most iOS and Android mobile browsers

remove .border-radius mixin and replace with standard border-radius property, since -webkit-* and -moz-* are only needed for older versions