Ignore some modules in autodoc

So it turned out to be a stupid mistake. Since some tools generate a scaffold for api documentation sources, those files were left laying around and triggered bad imports.

How this was found:

• sphinx has multiple levels of debug logging which do not normally get activated
• you can see which lines trigger imports by debug output like

 [autodoc] /path/to/the/doc.rst:158: input:
 .. automodule:: app.module.name
    :members: