Support 'Organize Imports' feature

[akosyakov]

It should:

• remove unused imports;
• remove duplicate imports;
• add imports for unresolved elements;
• ask a user to disambiguous imports in the case if several can be used for an unresolved element.

[basarat]

Personal Opinion: Nice idea for quickfixes / additional refactorings to be added into release 2.1 : https://github.com/Microsoft/TypeScript/wiki/Roadmap#21 🌹

[johnnyreilly]

I'd love to see this implemented.

[akosyakov]

It would be also nice if this feature respects index.ts files and imports stuff with the shortest possible import declaration.

[niklas-dahl]

would be awesome if it could unite imports, too.

from

import { Component } from '@angular/core';
import { Input } from '@angular/core';

to

import { Component, Input } from '@angular/core';