My intention is to apply a copyleft the source files. But actually,
the reasoning is a little different:
I requested help from the community around the fsf and the experience
was very bad. Each reply was followed up with questionable offers to
receive further input or buy useless stuff. The community appears to
be trapped by their own tooling.
I do not want to join such a community currently, because I am not able
to determine the entire scope of their actions.
My intention is to 1. open the code, 2. receive changes.

enable the c language implementation.

in preparation of config-dir.
The config-dir was renamed to cache-dir, since it holds files for
caching. The path already implied this, but the implementation was dirty
(probably because of the previous nature of zamba as a scheme language
          server).

Anyhow, this commit additionally enables zamba to correctly iterate
files from the current-working directory, which is a pretty simple
implementation, but complements vim very muc...