* use different eslint config for es6 and es5
* remove confusing eslint/baseConfig.js & add more eslint setting for es5, es6
* more clear way to run eslint on es5 & es6 file
* seperate ESNext, ES6, ES6 path, and use different lint config
* rename eslint config file & update eslint rules
* Undo yarn.lock changes
* Rename a file
* Remove unnecessary exceptions
* Refactor a little bit
* Refactor and tweak the logic
* Minor issues
Did find and replace in TextMate.
```
find: (?:( \*)( ))?Copyright (?:\(c\) )?(\d{4})\b.+Facebook[\s\S]+(?:this source tree|the same directory)\.$
replace: $1$2Copyright (c) $3-present, Facebook, Inc.\n$1\n$1$2This source code is licensed under the MIT license found in the\n$1$2LICENSE file in the root directory of this source tree.
```
