rpc/v0: gofmt and small comment

Author:    Alex Tran Qui <alex@katalysis.io>
Date:      Tue Jan 24 23:00:38 2017 +0100

licence: remove various GPLv3 copyright headers;

event_new: remove unused package that had been copied for discussion

monax: lingering eris -> monax company rename

licence: last pass, further cleanup

rpc: add AssertIsRPCResponse as marker method for restricting implementation of interface to actual RPCResponse types