TS build optimizations

[kirill-konshin]

Use incremental flag

https://github.com/Microsoft/TypeScript/wiki/What's-new-in-TypeScript#faster-subsequent-builds-with-the---incremental-flag

Use project references

• BLOCKER TypeStrong/ts-loader#851
• https://github.com/RyanCavanaugh/learn-a
• http://www.typescriptlang.org/docs/handbook/project-references.html

Webpack optimization

https://medium.com/@kenneth_chau/speeding-up-webpack-typescript-incremental-builds-by-7x-3912ba4c1d15