Serve unstyled, static content to versions of Internet Explorer 10 and lower

[schalkneethling]

There are a couple of reasons for this:

1. Our user base for these versions of Internet Explorer in incredibly low but, we still want them to be able to access the main content of the site. If we serve CSS and JS that does not work and throw tons of errors, it creates a negative user experience. We want to be sure that we do not add a maintenance headache here so, this should fallback to pretty much plain HTML with some widgets hidden with CSS.

2. We can adopt modern JavaScript, and use Babeljs to compile our JS down to a baseline. When we cut out everything less than IE11, our baseline generally has better support for modern JS. This means less down compilation. The result being a much smaller kb size for the resulting JS files.

3. Lower cost for users of low end hardware and old tech without blocking them from content.

Proposal

Serve only HTML with one simple CSS file that hides elements on the page that requires JavaScript to function.

[schalkneethling]

We can also get rid of the html5shiv. It is a tiny script but, one less dependency.

[schalkneethling]

This will also allow us could get rid of selectivizr, yet another dependency.