[Fixes #15911] Examples — Fixes navbar issues if brand is empty

[kkirsche]

This includes the navbar fix. I did not notice any difference with the footer code so I did not include that.
Fixes #15911.

[cvrebert]

Note that :empty isn't supported by IE8, but we can probably spin this as a progressive enhancement.

[kkirsche]

That's interesting, thanks for sharing that. I wonder why IE was so late when it was supported by FF 1.0 (2004) / Chrome 1.0 per MDN

[mdo]

Simpler fix in 05513c5.

Rather than account for weird empty states, this just makes the component more durable. The padding goes on the heading and the header gets a clearfix to ensure floats don't bust the flow.

[kkirsche]

Sounds good. Thanks for that info @mdo

[mdo]

@kkirsche In general, it's best to solve things like this with fewer exceptions to individual components. The presence of an element shouldn't have much of an unexpected affect on it's parent like that. It was an oversight on my part of not clearing floats properly. Hope that helps shed a bit of light on it :).