matrix-js-sdk

7a02c5d1 - Add concept of 'sentinel' RoomMembers which watch state at a particular point in time.

Add concept of 'sentinel' RoomMembers which watch state at a particular point in time. New sentinels are only created when the RoomMember state changes, so we don't needlessly deep copy RoomMembers f.e. MatrixEvent. Sentinels co-exist with RoomState.members which are single instances to which listeners can be attached. This gets the best of both worlds (don't have to keep re-attaching listeners on member changes, don't have needless memory consumption).