Added a more informative and styled fallback message for non-html5 browsers

...that also have JavaScript disabled

We often use a very simple fallback message like "Video Playback Not Supported" or just exclude the fallback message all together, but we should have something better there.

This only applies to browser that have no HTML5 video support AND javascript disabled. If javascript is enabled, video.js should still handle the video and show the appropriate no-support icon/message.

Some challenges here is that, without javascript, we can adjust the size of the paragraph to match what the video player would look like. In stead I created a 300x150px square with the message inside that centers itself. It's hard to say if that's the best approach across all use cases.

Also, @mmcc is working on the page on videojs.com that this message will point to.