* refactor: convert RoomViewStore from flux Store to standard EventEmitter
Parts of a series of experimental changes to improve the design of stores.
* Use a gen5 store for RoomViewStore for now due to lock handling
* Revert "Use a gen5 store for RoomViewStore for now due to lock handling"
This reverts commit 1076af071d997d87b8ae0b0dcddfd1ae428665af.
* Add untilEmission and tweak untilDispatch; use it in RoomViewStore
* Add more RVS tests; remove custom room ID listener code and use EventEmitter
* Better comments
* Null guard `dis` as tests mock out `defaultDispatcher`
* Additional tests
06c4ba32cd