e.g.
 - ability to log ip addresses of respondents
 - configurable bind address
 - reasonably sane defaults (hopefully)
 - survey name as part of output file names

this is just a quick barebones server, which doesn't really do yet what
it is supposed to or what the guile version did.

(previously, it tried to use ascii encoding and would fail)

The idea is that it can accept surveys sent to it. Note that in an actual
deployment it should have at least some rate-limiting, since actual validation
of input is impossible if they are encrypted – i.e. this is bascially a pastbin.

It may, however, be possible to require signing answers for survey with access
restrictions, or do a challange/response type thing before allowing submission.