ncm-named: fix retrieval of named root directory from sysconfig

Fixes #241

Wait for more unit tests to be added before merging this PR.
I still do not agree with this component touching `chkconfig`. Starting and stoppping daemons are appropriate actions for a component. Modifying what will be enabled at boot time is the domain of `ncm-chkconfig` and its platform-specific alternatives. 

I know this reflects the old behaviour, but the old behaviour is old and wrong, and from a time when we didn't have the practices or experience we have now. Our policy for a long time has been to leave handling of chkconfig-like actions to `ncm-chkconfig`, and IMO that's the right thing(TM). If this deserves an exception, I want to know why. If not, this is the perfect time to fix the mistake. :)