Improve ncd status logging

Fixes #12.

In addition, restore the original formatting of ncd status line in `/var/log/ncm-cdispd` to avoid breaking existing parser for this file (I know that line is parsed to raise attention when a component failed).

Still work in progress, would like to add the list of failed components as described in #12.
hmm, if this is going to be frequently used, i propose to add to CAF (one or more) of:
 * `$p->get_executable()`
 * pass optional loglevel to `is_executable`  to log the failure
 * `$p->execute_if_executable()` (better to find shorter name like `eie` :smile: ) which is basically
```perl
sub execute_if_exists 
{
    my $(self) = @_;
    if ($self->is_executable()) {
        return $self->execute();
    } else {
        $self->{log}->error("Command ".$self->get_executable()." not found or not executable");
        return 1;
    }
}
```