- Update the room display name and its avatar url when the Room Summary is updated on state events change (see `[session: updateRoomSummary: withStateEvents:]`).
- Store the riot display room name and its avatar url in the Room Summary.
- Add a new category `MXRoomSummary+Riot` to handle avatar display.
TODO: Increase file store version in `MXFileStore.h`.
- some hairlines being too bright
- fading behind dialog modals being white rather than dark
- grey highlight bar in room list being too light (i think)?
Recents List: some room avatars have an unexpected black background.
We apply here the new property `defaultBackgroundColor` defined in MXKImageView class to initialize correctly image background.