Don't immediately return promise within newly created promise

[DustinCampbell]

Fixes #804

[narf]

Is it normal that rejection of launch promise is not handled here?

[DustinCampbell]

It's intended that rejection will be propagated to the caller, which is in server.ts here.

[narf]

If there is no reject callback AND the "launch" promise is not returned anywhere, I'm quite sure that the error will be silent.

This should be the correct way to bubble the error to the caller:

launch(details).then(result => {
    // async error - when target not not ENEOT
    result.process.on('error', reject);

    // success after a short freeing event loop
    setTimeout(function () {
        resolve(result);
    }, 0);
}).catch(reject);

[narf]

Why not putting all the code in a Promise like previously?
Any error there will end up in a throw which is not really what a function returning a promise should do.

[DustinCampbell]

Any exceptions should ultimately be propagated to the caller in server.ts. The catch() there handles all rejections and exceptions.