* Add automatic exporting of pages with no getInitialProps

* Add support for exporting serverless to static
and serving the html files during next start

* Fix missing runtimeEnv when requiring page, re-add warning
when trying to export with serverless, and update tests

* Update flying-shuttle test

* revert un-used pagesManifest change

* remove query.amp RegExp test

* Fix windows backslashes not being replaced

* Re-enable serverless support for next start

* bump

* Fix getInitialProps check

* Fix incorrect error check

* Re-add check for reserved pages

* Fix static check

* Update to ignore /api pages and clean up some tests

* Re-add needed next.config for test and correct behavior

* Update RegExp for ignored pages for auto-static

* Add checking for custom getInitialProps in pages/_app

* Update isPageStatic logic to only use default export

* Re-add retrying to CircleCi

* Update query during dev to only have values
available during export for static pages

* Fix test

* Add warning when page without default export is
found and make sure to update pages-manifest
correctly in flying-shuttle mode

* Fix backslashes not being replaced

* Integrate auto-static with flying-shuttle
and make sure AMP is handled in flying-shuttle

* Add autoExport for opting in

* Add .d.ts files

* Drop next declarations from index.d.ts

* Bring back number of errors

* Fix more errors

* Fix rewriteUrlForExport

* Moved server/lib/utils.js to Typescript

* moved _app.js to Typescript

* Moved _error.js to Typescript

* Added argument for custom props in _app and _error

* Moved _document.js to Typescript

* updated one test

* Updated types and added a validation for _document props

* Improved types

* Fixed some types

* Updated AppType

* Fixed some tests

* Added missing import

* Removed a not very useful type

* Fix missing type

* Move @types/styled-jsx

* Fix typescript errors

Upgrades `standard` to major version 12

* Revert #6030

* Fix _app childContextTypes

Continuation of #5945 

Fixes parts of #5716. I had some issues with the test suite but I'm fairly certain that I got it working correctly.

- 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

- compile default pages correctly into `.next`
- add missing runtime dependencies

- Implements Lerna
- Moves all source code into `packages/next`
- Keeps integration tests in the root directory

* Expose pages/_app.js

* Add tests for _app and _document

* Uncomment deprecation warnings

* Add documentation for _app, improve documentation of _document

* Update docs / test for _document

* Add _document to client compiler in development

* Add missing app.js to comment

* Only warn once

* Add url-deprecated error page

* Combine tests

* Yse same message for all methods of ‘props.url’

* Update docs around _app

* Update documentation

* Quotes

* Update table of contents