Update analytics test with ES config and namespace
WIP on rebuilding handoffs

* Start to replace HandoffTranslator with `ipc-rpc`, a simple RPC module that
  runs over `process.send` and provides callbacks.
* Build tests for master -> master handoff
* Give sources the ability to specify whether they should go through handoff
* FIXME: Stream group support isn't implemented yet
* FIXME: Other handoff modes are broken at the moment