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.

Fixes #5471: Remove color from .navbar and .navbar-inverse and reassign to .navbar-text to prevent unintended cascading

* When :empty, display: none;
* Add documentation for change in behavior

fixes #5542: move '.hero-unit p' font-styles to '.hero-unit' so they apply to all elements, including ul and ol, within the component.