[PATCH 1/3] Adding an S-expression structured output printer.

[Peter Feigl]

The reason I would like to have this included in notmuch is because I
use it for an Android client (http://www.nexoid.at/tmp/search.png).
It is written in Kawa Scheme, and works on all Android devices I have
access to :) Only reading for now, composition later.
After some cleanup I'll make it available to anyone
interested. S-Expressions are much easier to use than json here.

Greetings,

Peter