Add process.parent by duplicating all fields explicitly

[webmat]

Doing this via normal field reuse is pretty tricky at this time. This is the
first time a field set gets reused under a different name ("process" nested as "parent").

So for now I suggest simply duplicating all fields.

In order to avoid issues with this duplication:

• I call this out and explain it at length in a comment at the top of the process.yml file.
• Each duplicate entry is directly below the entry it copies in this file
  (e.g. process.pid is directly followed by process.parent.pid)
  • Note that the generated docs are sorted by the flattened key name. So all parent.*
    fields will actually be grouped in the generated files.

Closes #597.

[webmat]

@ruflin @andrewkroh I'd like to get feedback on the approach I'm taking here. I think it's the pragmatic approach to get this done sooner than later, but it may be controversial.

Also cc @andrew-goldstein, as this solves your issue #597 :-)

[ruflin]

I'm ok with getting this in as a hack. We must make sure to get a proper implementation long term as otherwise it is guaranteed that the two get out of sync.

[webmat]

Totally agreed. I will have to adjust this PR because we've recently been adding a few other fields to process.*. So I'm already feeling the pain ;-)

Work has started on adjusting the scripts in this branch, but still very much a WIP.