Vector should display consistent ordering on timelines.

[ara4n]

If I change my display name with /nick whilst typing fast, i find the messages are locally echoed before the nick change remote-echo arrives, so I end up with an inconsistent timeline relative to other views of the room. Refreshing fixes it.

[ara4n]

This is actually a very general problem - whenever I send messages, the local echos may end up entirely misordered relative to the remote echos. This is a real shame as the DAG obviously has a well defined ordering which Vector should surely preserve.