updated the library to allow ETHInterface

I also made the InterfaceBlock slightly more generic; both UDP and
ETHInterface are InterfaceBlocks, kept in the (newly renamed)
InterfacesList.

This could be made into a map[string]InterfaceBlock.
rectified comment
UDP and ETH Interfaces are now arrays by default
UDP and ETH Interfaces are now arrays by default
Merge pull request #5 from inhies/patch-1

CJDNS config changed

Thanks, inhies!
Merge pull request #6 from inhies/patch-2

Update to match the new config

Thanks again, inhies!