vscode code base - migrate to consuming typings from npm as supported by TS 2.0

[egamma]

The code base still includes a typings folder.

Now, that we are on 2.0 we should consider migrating to consume typings through npm.

[dbaeumer]

Blocked by jrieken/gulp-tsb#51

[dbaeumer]

Did not make it for November.

[dbaeumer]

Some improvements happened but we still have quite some code referring to d.ts files in the typings folder.

[gulshan]

Is it still relevant?

[dbaeumer]

Yes, there is still a typings folder mainly because we customize some of the typings. Need to investigate which once we need to keep.

[dbaeumer]

I am closing the issue. I looked over the typings folder and there are now quite some new typings because we forked existing npm modules. For the once were it looked reasonable we have them in the package.json now (see https://github.com/Microsoft/vscode/blob/master/package.json#L62)