Vuetify: [Feature Request] v-checkbox / v-simple-checkbox - loading state

[jacekkarczmarczyk]

Problem to solve

https://codepen.io/anon/pen/KONvrR?editors=1010

Proposed solution

<v-checkbox v-model="model" :loading="loading" />

[dsanders11]

This is almost a bug fix rather than a feature request, since the documentation documents the loading prop (incorrectly, says it's a linear progress bar) and there is a loading prop, it just does nothing.

[johnleider]

An unfortunate downside when extending. We'll get it resolved.