html-loader support

[joshgillies]

It would be excellent is we could pass our templates into something like html-loader, as a way to then for example pass image refs into various other file loaders.

Theres some similar work being done over here: https://github.com/vuejs/vue-loader/ that could be used for inspiration.

[joshgillies]

This shouldn't be too complicated to implement, as we're already requiring users of this loader to have a template file as html we can simply require it when present and let webpack pass it onto an appropriatly configured loader.