Add support for imported exports

[kpdecker]

Adds support for

export * from 'module';
export { function } from 'module'

providedExports field appears to be around for all of Webpack 4. If prior webpacks are supported still, then will need a simple adapter layer.

Approached this in additive fashion to reduce the risk of this PR. I do have a stash locally that replaces the custom traversal logic glad to include that in this PR if desired. Mostly deletes the custom parser hooks.

Fixes #15