translatable challenges

Problem/Motivation

I am french-speaking, and so is my site. Having a CAPTCHA in english severely limits accessibility to the site.

Proposed resolution

Allow challenges to be translatable.

Remaining tasks

* make upstream support translation
* integrate that in the module

Alternative route: do not make this a web service, but integrate the upstream code directly into the module.

User interface changes

We'd probably need an admin interface for the challenge/response or at least choose the language. Now the problem is this whole module depends on the api.egglue.com service, which doesn't seem to have a clearly documented API - it is unknown whether upstream actually supports such a feature.

API changes

Probably multiple.