Add support for es6 interpolation

[sheerun]

Hey,

I'm re-writing angular 1.0 app and I'd like to include partials directly from templates, like so:

<div id="gallery">${require("./partials/gallery.html")}</div>

instead of relying on ng-include:

<div id="gallery" ng-include="'partials/gallery.html'"></div>

This commit adds in 2 lines of JS support for es6 interpolation in any place of the template.

I find it very useful, I hope you too.

[sokra]

As this is a breaking change, it should be better enabled with query parameter i. e. html-loader?interpolate

[sheerun]

If I change this, will you accept this PR? :)

[sokra]

yep, if everything is fine. It looks like a useful feature.

But please add some tests for this.

[sheerun]

@sokra I've rebased, added a flag, updated README, and added the tests. All good?

[sokra]

Thanks

[sheerun]

Cool :) Could you release minor bump?

[sokra]

Soon...