549 noderesults and friends

For review.  @ysahnpark please take a look.  @mlippert, you're of course most welcome to as well.

There are a number of open questions still in here:
* We do error checking on expired Hub-Session notifications coming back from the mocked AMS.  These might not be terribly realistic anymore, as the IPS doesn't really care.  Perhaps some day though the AMS may want to return an updated Hub-Session to us or something.  I dunno.  Are we okay with these tests still in here?

* Related to the above, Hub-Session lives as a top-level element in the sequenceNode that we store in redis: {hubSession: <sequenceNodeKey>, seqNodeInfo: {hubSession:<hub sess>, sequenceNodeContent:<value>}}
Do we want to leave that there or purge it?  I don't think we have a clear picture from Nyo and his team yet about Hub-Session, GUIDs, sequenceNodeIdentifiers, and the like and so I'm inclined to leave it for now.

* If Nyo agrees to the IPS->AMS proposal, we'll probably only have one endpoint for IPS->AMS regardless of interaction/submission.  If that's the case we'll probably want to consolidate amsproxy.sendInteraction and amsproxy.sendSubmission, don't you think?