Fix ncm-cdispd forgetting about failed configuration modules

- Fix function used to run ncm-ncd not returning ncm-ncd status
- Use `CAF::Process` to execute ncm-ncd
- Properly retrieve ncm-ncd status (fix for the buggy value that has
always been returned)
- Improve debug logging

Fixes #4
I understood this was one change we wanted to propagate everywhere: replace backticks by CAF::Process. This is in particular a requirement for tainted mode if I'm right.