Tweaks to the semantics for sending RRs and handling room switches
Tweaks to the semantics for sending RRs and handling room switches

* Only send read receipts when we are at the bottom of a room; this is a simple
  and effective way of stopping the green bar of doom from jumping down the
  room slightly behind the scroll.

* Jump to read-up-to mark when switching back to a room if we were following
  the live timeline before.

matrix-org/matrix-react-sdk,aperezdc/matrix-react-sdk,aperezdc/matrix-react-sdk,aperezdc/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,aperezdc/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk