Explore how to leverage TypeScripts new typings support

[kieferrm]

With 2.0 TypeScript changed how typings are acquired.

• explore how to leverage the new typings story for TypeScript
• explore how to leverage the new typings story for JavaScript
• explore automated acquisition of typings

[kieferrm]

Here are findings from the exploration.

1. With TS 2.0.5 automated typings acquisition story works well. There are several glitches but nothing unsolvable in for the October release.
2. JS users still need to a jsconf.json file in order to get code completions. We should look into automatically/virtually injecting the "project marker".
3. When opening a new js folder/project the TS server determines all modules/libraries and starts acquiring their typings. If the typings are not yet cached this can be a work intensive process with a lot of CPU usage. I.e. we need to inform users that something is happening.
4. Typings can refer to a different version than the actual module/library. We should look into letting users know how proposals are computed (when the ask for it).

[kieferrm]

We should change the default to not acquire typings out of the box for now.