Here we put Ado::Command::* specific configuratuon files.
The files must be named after the commands for which they contain configuration.
A command Ado::Command::hello will search its configuration in
$app->home->rel_dir('/etc/commands/hello.conf').
The file must return a HASHREF:
(the app keyword containing the current app instanc is available for use)
#hello.conf
{
  somekey =>'somevalue'
  #...
};
