Servicebus updates

- Include underscore in package.json
- Replace in-memory schoolCheers with direction checking of socket
rooms. This simplifies potential scaling issues if we need to go
multi-instance for scaling. Also simplifies servicebus/local switching
- socket sessions/rooms now can be optionally stored in service bus
depending on config. This is turned off in Azure now until we decide to
scale across instances.
- made matching changes to client.html to account for backend changes
- added a /listcheers method to dump out current cheer mapping. This is
useful for admin, and to allow a worker to push info into DB for
storage and visualisation.
Client and backup fixes to merge with Shawn's code

Fixes bugs I introduced earlier when not properly combining early changes
Now code emits an updated cheerCount directly to client that releases the cheer button
Fix for getAllCurrentCheerers

Don't show total count. It's not right and would be redundant anyway.
Merge branch 'servicebus'