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

fixes #5494: style invalid fields as invalid regardless of required-ness

Merge branch '2.1.2-list-inline' of https://github.com/andriijas/bootstrap into andriijas-2.1.2-list-inline

Fixing various spelling typos in the docs.

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

Change example email addresses to use RFC 2606 reserved example domain.