...that are sent from another client.
Also look up the profile data for the user's LINE account on sync,
including at startup, so that there's always a puppet available.
- Handle "decrypting" state of messages
- Handle lazy loading of emoji
- Better handle lazy loading of images/stickers
- Improve reliability of message sending, especially when sending
several messages quickly
- Use m.sticker events for inbound stickers instead of m.image, and add
a config to optionally use m.image if desired
- Use proper sizing for emoji, and add config to scale them since they
are somewhat small
- Deduplicate stickers as best as possible (works until they get a
different blob URL)
- Add config to disable bridging stickers/emoji
- Send m.notice for inbound messages of unknown type
