Handle single file components

[backflip]

Demo: https://github.com/jensfranke/feller/pull/2

Turned out to be a bit more complex than anticipated, unlike https://github.com/lixinliang/require-extension-vue/blob/master/index.js we need a transpile step with babel first (assuming we want to write ES2015 modules).

[swey]

I based on your approach and made some refactoring and started to add the support for explicitly defined props: https://github.com/swey/fractal-vue-adapter/tree/feature/sfc

But still one problem to solve

[swey]

Also see #2