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 don't want to explain it again but I'd like to see this in 14.6.0 and thus I tried to have the changes as minimal as possible (in this sense I could have kept the backquoted command but thought it was a good time to use CAF::Process). Building the command as an array rather than splitting the string is desirable but too intrusive for this time, IMO.