Make M-g M-l reuse existing window (e.g. side window) #131
Description
It would be good if M-g M-l reused an existing window, especially when the room list is shown in a side window.
It looks like ement-room-list's display-buffer-action argument needs to have display-buffer-reuse-window added, but that doesn't appear to be enough, because the window doesn't get selected, so maybe we need to call select-window also.
Suggested by @jeffbowman.