VSC self-documentation

[Dridi Boukelmoune]

> I have a small, 500 LOC, json parser in C we can use, so that is
> not going to drag in a dependency.
>
> If we're going to bite the JSON bullet, the other places it makes
> sense to use it, is for the vcc_if.c::Vmod_Spec data structure
> which explains the contents of a VMOD to VCC.
>
> Given that we are going to expand what VMODs can contain, that
> "minilanguage" needs expansion too, so all in all, I think we
> are over the threshold were JSON makes sense.
>
> ... but I still feel dirty using JSON to pass data structures
> from one C-program to another, or as it may be, from a python
> program to another.

There are other solutions for this kind of descriptors, and you could
probably get a msgpack [1] subset implementation with the same-ish
amount of code and get the benefits of actual typing (int, string,
etc) and easier parsing.

Dridi

[1] http://msgpack.org/