Debian packages and listening interface parameter

Hi,

I have made the following modifications to your code, maybe you want to add them to your repo:

* Added an initial debian folder for the creation of Debian/Ubuntu packages.
* Moved  *.c and *.h files to a new src folder.
* New Makefile with debuild target to create Debian packages.
* New -i parameter added to the server to allow listening only on a specific interface (v0.36)

Also, we have created a chef-cookbook to deploy the service automatically: https://github.com/SpringerPE/chef_pe_carbonrelay 

Thanks and best regards!