Fixes for building with Node 4.x

[tschaub]

The generate-info.js task fails on Node 4.x because process.stdout.write() is now async, and our exit handler is called before the child JSDoc task's publish method finishes writing to stdout.

Because the generate-info.js task fails, the build.js task does as well.

It would be nice to use a published version of JSDoc. I'll ask when the next version might be published. I think this is a big enough issue that we should merge a fix before 3.10 is released - even if it means going with an unpublished version of JSDoc. I also need to confirm that the API doc output is still good.

Fixes #4127.

[probins]

Promises are natively supported in Node 4. You probably don't need bluebird here.

[ahocevar]

Looks great @tschaub, please merge.

@probins I think for now it makes sense to still support older versions of node, so using bluebird should be fine.

[fredj]

Can we use jsdoc version 3.3.3?

[tschaub]

Can we use jsdoc version 3.3.3?

See jsdoc/jsdoc#1070. We need this commit: jsdoc/jsdoc@7d9fc7b (which is not in a published release yet).

The change we need is included in jsdoc/jsdoc@bd1cb9d. Which is understandably the source of a lot of confusion.

[tschaub]

I've published a forked version of jsdoc. I don't intend to maintain this fork, but I'd very much like to get our builds working with both Node 4 and npm 3. The master branch of jsdoc has the changes we need for Node 4 (the changes in jsdoc/jsdoc#1082 would make this even better). If a new version is published with these changes, we can switch back.

[tschaub]

Note that when/if there is a jsdoc version published that works with Node 4, we need to replace all jsdoc-fork in our source with jsdoc.