Fixes #85.  Thanks to @jfmcbrayer for reporting.

Closes #88.  Thanks to @ericsfraga for suggesting.

i.e. (ement-auto-view-room-display-buffer-action), and use
in (ement-room-view).

Oops, they were being inserted unconditionally in new room buffers.

This should be correct, and omitting it must have been an oversight...

This still isn't quite perfect, but it seems to be about 99% so, and a
significant improvement.

Thanks to @gearoid1:matrix.org for reporting.

Need to check both state and invite-state.

Fixes #81 (which only happens on an unreleased Emacs version).  Thanks
to Tassilo Horn (@tsdh) for reporting and debugging.

Also improve error message.

Lispy sometimes makes this unnecessary change.

Thanks to @tsdh for suggesting.

Fixes #80.  Thanks to Tassilo Horn (@tsdh) for reporting.

Thanks to Tassilo Horn (@tsdh) for suggesting.

Fixes #79.  See also 0541916b, #34,
and #73.

Thanks to Tassilo Horn (@tsdh) for reporting.

Makes each type of event easier to find in long lists of membership
events.

On the rare occasion that the ement-taxy buffer is opened before room
avatars have been fetched, the generated avatars would fill the cache,
and the downloaded ones would never be shown.  Now, killing the buffer
will discard the cache (which is a good idea, anyway, otherwise it
becomes almost like a memory leak).

* ement-room.el (ement-room-dnd-upload-file): Add.
(ement-room-mode): Register dnd function to upload file when dragging
them to an Emacs frame.