Remove Babel
Use .es6 ext for ES6 sources
Add Result#content
Clean up code styles
Show deprecated message only once
Typo
Fix 4.0 compatibility
Lint code with ESLint
Add Warning class
Add Result#messages
Remove outdated comments because we have API.md
Add LazyResult for future async plugins
Use ES6 export statement instead of module.exports
Use ES6 import
Replace Traceur to ES6 Transpiler
Convert Result to ES6