Rich tuples support

[marcoqu]

Support for new tuple features introduced in typescript 3.0

export type A = [number, number]
export type A = [number, number, number?]
export type A = [number, number, ...number[]]
export type A = []

This also removes the --strict-tuples option as it is now obsolete.

[domoritz]

This is awesome. Thank you so much. I'll review this today.

[domoritz]

Works great, thank you!

[domoritz]

Thank you so much @marcoqu do the PR. It works great and fixed an issue in Vega-Lite! Since you have contributed in the past as well, I was wondering whether you want to get contributor rights on this repo? You could push branches and close issues and accept PRs.