* Add initial AMP implementation

* Implement experimental feature flag

* Implement feedback from sbenz

* Add next/amp and `useAmp` hook

* Use /:path*/amp instead

* Add canonical

* Add amphtml tag

* Add ampEnabled for rel=“amphtml”

* Remove extra type

# Description

* Fixes incorrect assertion of configuration file in the `with-hashed-statics` README as well as adds link to line for updating

# Conflicts:
#	lerna.json
#	packages/next-server/package.json
#	packages/next/package.json

Add options to customize webpack config section.

* Set default `Error` status code to 404

This is an appropriate default behavior because:

1. When the server encounters an error, the `err` property is set.
2. When the client-side application crashes, the `err` property is set.

This means the "only" way to render the `/_error` page without an error
is when a page is not found (special condition).

Fixes #6243
Closes #5437

* Add new integration test for client side 404

* single quotes

* Remove unused variable

* Standard needs to go away

* Whoops

* Check for null status code in res and err

* Only check response for valid statusCode

* Add `module` as server fallback main field

* Test that a module only package can be imported

* convert export default anonymous functions into named functions

* change examples to function declaration and split export in classes

* change NextHead name to Head and rename component

`initialProps.styles` is a React node, but not guaranteed to be an
array, so we can use a fragment to concatenate additional styles.

See https://github.com/DefinitelyTyped/DefinitelyTyped/issues/32932#issuecomment-462372319

* extract request login from auth

* add clarification that the monorepo is for deploy in Now only and fix typo

* Refactor HOC

- add authorization to HOC
- add displayName to HOC
- remove unnecessary `run`s in local routing

* Updated examples for build-time env configuration for v8

* Add comment to build time config example with how to include entire .env

# Conflicts:
#	examples/with-apollo-and-redux/README.md
#	examples/with-sentry/README.md
#	examples/with-sentry/package.json
#	examples/with-sentry/pages/_app.js
#	package.json
#	packages/next/build/webpack-config.js
#	packages/next/client/index.js
#	server/document.js
#	server/render.js
#	test/integration/production/test/index.test.js

As per discussion in #6165, I removed the `passHref` in `Link` as
they're unnecessary.

Changelog https://github.com/zeit/styled-jsx/releases/tag/v3.2.1

This reverts commit ab46c451.

* Bring in terser-webpack-plugin (backport #6231 to master)

* Use correct path for ignore

* Comment out schema

* Bring in terser-webpack-plugin

* Ignore terser from linting