Added the answering peer as parameter to the response block of request response commands

Fixes issue #5
Thanks to @gekitz for the feedback on this issue.
Switched public command identification to classes for starting and stopping discovery.

This commit fixes #4. Commands have been identified by their name and their class in the connectors interface before. This approach is not clean and unified to the use of classes only now. Thanks for the feedback on this issue to @gekitz.