Move back to JavaScript

[bcardarella]

Coffeescript, while I like the syntax, is not future-proof. See: http://meta.discourse.org/t/is-it-better-for-discourse-to-use-javascript-or-coffeescript/3153/11

It also adds extra complexity to the build and release process that has caused issues. Some contributors have updated the coffeescript without generating the JavaScript. Let's just remove this extra step.

We can start with the generated JavaScript from the existing build.

[bcardarella]

That being said I would actually like to move to an actual build system like minispade. We should also add JSHint.

[tagliala]

I would like to move to es6 + webpack base builder