[noise] Python scripts for manipulating patterns

[Naveen Nathan]

>      Code-gen would be particularly useful, Noise adopters so far are
>      preferring simple "compiled" -code rather than general libraries.
> 
>      I feel like you could get pretty far just with per-language files
>      containing some text templates, but I'm sure devil's in details...
> 
>    I did think about that.A  One "devil" is the back end crypto primitives -
>    the API's for those are all over the map with no consistency.A  But if
>    that can be pushed off to a plug-in class/template, then it may be doable.

Agreed. I have an implementation lingering[1] that needs some polishing before
I can release it. The hardest part I found (which I think Rhys warned me about
during early stages of implementation) is collecting the crypto primtives
and wrapping them. It is a fairly yucky process and I'm kind of stuck with
Python 2 compatibility at the moment.

There is however consistency in the Noise spec on how the crypto primitives
are accessed, and if autogenerated code assumes this interface, I think
that is sufficient. The most difficult part in implementing Noise (imo)
is collecting (or implementing) the primitives. The rest is fairly automatic
and code autogeneration makes a lot of sense.

[1]: https://github.com/nnathan/noiseprotocol