There's still a few Typescript helpers in use, but regenerator is added by Babel after this change, as it was already in the bundle it'll drop bundle sizes by quite a bit, eg _app.js becomes half the size.
- Replaces taskr-babel with taskr-typescript for the `next` package
- Makes sure Node 8+ is used, no unneeded transpilation
- Compile Next.js client side files through babel the same way pages are
- Compile Next.js client side files to esmodules, not commonjs, so that tree shaking works.
- Move error-debug.js out of next-server as it's only used/require in development
- Drop ansi-html as dependency from next-server
- Make next/link esmodule (for tree-shaking)
- Make next/router esmodule (for tree-shaking)
- add typescript compilation to next-server
- Remove last remains of Flow
- Move hoist-non-react-statics to next, out of next-server
- Move htmlescape to next, out of next-server
- Remove runtime-corejs2 from next-server
