Fixes #3106

* Resolved issue #2971

- changed h2 to h1 in template to adhere to accessibility guidelines.
- Added h1 styles to maintain same font size.

* Added header tag to template

Corrected templete to use semantically correct header tag for header instead of div

* Added className for App-title

- Added className="App-title" to h1 tag
- Changed CSS selector to target class instead of element

* Updated react-error-overlay to latest Flow (0.54.0)

* Revert "Updated react-error-overlay to latest Flow (0.54.0)"

This reverts commit 6deaffbd.

* Fixed unit tests.

* Updated code as per code review.

* Fixed code as per code review.

* Updated the code as per review.

* Auto-detect running editor on Linux for error overlay

Basic support of auto detecting running editor for #2636.
Tested on Ubuntu 16.04.
It detects few editors. JetBrains products should start by
wrapper like /usr/local/bin/webstorm. Otherwise it takes a
lot of time to open editor.

* Comments fixed.

* List all processes owned by you

* Comment rewording

* Clean target directory before compiling overlay

* Use rimraf

* rerun prettier for all files

* pin prettier to 1.6.1

* Reload the page when an error has occurred
Fixes #3096

* Use a global boolean instead

* Switch to unix path separators before normalizing path for Windows compatibility

* Add comment for posterity

* Revert "Add comment for posterity"

This reverts commit 742bacee.

* Strictly add comment

The `npm install` script for outside usage instructions is outdated. Updated to match the package's current peer dependencies.

 - react-dev-utils@4.0.1
 - react-error-overlay@2.0.1
 - react-scripts@1.0.13

* Make error overlay file configurable

* Add fallback filename

 - react-dev-utils@4.0.0
 - react-error-overlay@2.0.0
 - react-scripts@1.0.12

* update babel-runtime dependency in react-error-overlay and react-scripts

`babel-runtime@6.23.0` have a dependency on `regenerator-runtime@0.10.5`
`babel-runtime@6.26.0` on `regenerator-runtime@0.11.0`

> npm ls regenerator-runtime

```
└─┬ react-scripts@1.0.11
  ├─┬ babel-core@6.25.0
  │ └─┬ babel-runtime@6.26.0
  │   └── regenerator-runtime@0.11.0
  ├─┬ babel-eslint@7.2.3
  │ └─┬ babel-traverse@6.26.0
  │   └─┬ babel-runtime@6.26.0
  │     └── regenerator-runtime@0.11.0
  ├─┬ babel-runtime@6.23.0
  │ └── regenerator-runtime@0.10.5
  └─┬ react-error-overlay@1.0.10
    └─┬ babel-runtime@6.23.0
      └── regenerator-runtime@0.10.5
```

* fix requested changes

* Convert react-error-overlay to React

* Update compile-time error overlay to use react-error-overlay components

 * Refactor react-error-overlay components to container and presentational components.

 * Make the compile-time error overlay a part of react-error-overlay package.

 * Use react-error-overlay as dependency in react-dev-utils to show compile-time errors.

* Run Prettier

* Move the function name fix into StackFrame itself

* Fix clicking on source code snippet to open the code in editor

* Use exact objects + minor style tweak

* Don't linkify frames that don't exist on the disk

* Fix lint

* Consolidate iframe rendering logic

* Remove circular dependency between react-dev-utils and react-error-overlay

* Fix lint

* Fix decoupling of react-dev-utils and react-error-overlay by moving middleware

* Deduplicate identical errors

* Debugging in WebStorm

* Fixed formatting for shortcuts

* Added note about default URL

* Fix docs for `printFileSizesAfterBuild`

* Add optionals parameters for `printFileSizesAfterBuild`

The service was rebranded to xervo.io and was completely shut down in April 2017

Fixing a small typo.

 - babel-preset-react-app@3.0.2
 - create-react-app@1.4.0
 - eslint-config-react-app@2.0.0
 - react-dev-utils@3.1.0
 - react-error-overlay@1.0.10
 - react-scripts@1.0.11

* Bump deps

* Fix linter errors

* Whoops

* Try to bump webpack

* Update peer deps to min for eslint 4.x

* use env variable to disable source maps

* Rename to use SOURCE_MAP with explicit value

* Update webpack.config.prod.js

* Move the reduction of the messages to a single place in the place it is used.

* Fix variable name

* Adjust the `checkIfOnline` check if in a corporate proxy environment
If the environment variable `https_proxy` is set, test that the proxy name is resolveable rather than 'registry.yarnpkg.com'.
This fixes #2832.

* Adjust to check yarnpkg.com first, then check the proxy address only if that failed

* Fix the order of arguments in spawned child proc

* Update react-scripts.js

* Remove a comma

* Update react-scripts.js

* bump wp3

* try bump babel-loader

* bump 3.4.1

* Allow importing package.json

* Remove package.json import from App.js template

* fix importing package.json

* Rename variable to reflect path is relative to root

* Check for both package & package.json in ModuleScopePlugin

* Use regex to check relative path to package.json

* Strictly enforce package.json extension on scope plugin

* Add allowedPaths to ModuleScopePlugin ctor and use it to allow app package.json

* Remove package.json import from App.js template

* Add package.json to react-scripts/template, show package version and name in the template

* Remove import package.json from template

* Remove template/package.json and its references in code

* Update ModuleScopePlugin.js

* Update README.md

* Re-enable flowtype warning

* Update eslint-plugin-flowtype dependency

* format UglifyJs error

* move formatBuildError to react-dev-utils

* fix readme

* use regex for plucking the path from stack

* make path human readable and fallback to show error if regex not matched

* rename to printBuildError and add link to the docs

* fix link indentation

* improve readibility + shorten link