ncm-cdispd code cleanup

Work in progress related to #8...

Discussion on cleanup goals is better placed in #8.
I had to resign adding `done_testing()`: it is not happy with the number of tests specified with `use Test::More`. And if I declare the number of tests in `done_testing()`, I don't get the `ok`.... Anyway, I don't know what it brings, except if you want to declare the number of tests at the end rather than at the beginning.