Problem with kernel.root_dir

[mialex]

Hi, I'm new with Symfony and it bundles, but faced with a problem.

• I use your bundle in a project without Symfony where Symfony DependencyInjection is implemented.
  Also I made it possible to use external bundles with the help of DependencyInjection container. And now I faced with the problem in the next file:
  https://github.com/richsage/RMSPushNotificationsBundle/blob/master/DependencyInjection/RMSPushNotificationsExtension.php#L32
  I don't have initialized kernel.root_dir and kernel.cache_dir as I don't use Symfony Kernel So I get an error there.
  Is it possible to make it optional? Or I should manually define kernel.root_dir inside my config?
• Also I see that you insist on using logger with LoggerInterface. In my case I would prefer to have logs as an error while sending a message and get it from service. (Like in Forms). So then I can get those error and process them by my own.

In case this bundle is reusable, looks like it is no. (from Symfony Best Practices: "Reusable bundles: meant to be shared across many projects.")