Unbundling

This is a first attempt, mostly for feedback for a dual bundled / unbundled testing workflow.

We always enable `useBundles`, then run unbundling prior to tests, unless running the `test:bundle` test, which ensures bundling is run.

Feedback welcome if this is the right approach or not.
Should add the option to specify task dependencies for this task:

```js
gulp.task('unbundle', getDeps(options, 'unbundle'), function() {
```

And then add "unbundle" to the default taskTree in gulpconfig.json