TypeSript support

• Added TypeScript support (examples uses TS, sandbox uses JS)
• Updated Babel, Webpack
• For field widget slightly changed format of formatValue() and sqlFormatValue() functions - argument rightFieldDef is now last one
• Added defaultValue in field config
• All fieldSettings will be now passed to widget props
• listValues and allowCustomValues moved inside fieldSettings

See:

• index.d.ts
• examples in TS (npm run examples)

TODO:

• Probably it worth adding comments in index.d.ts also.