In MUC, messages you send are broadcast to everyone in the room, including you. In certain cases, what is broadcast is may be different from what you sent. Examples include very long messages being redirected to a pastebin service or a multi-line message sent to an IRC gateway being split into multiple messages.

Currently Conerse.js shows the message that you sent, which may result in confusion.

To Reproduce
Steps to reproduce the behavior:

1. Open two instances of Converse.js
2. Join a MUC with some message-altering behavior with both instances
3. Send a message that would be altered
4. Compare what is shown between the two instances

Expected behavior
Messages subjected to server-side alteration should be shown as they are received, not as they were sent, as this is what everyone else sees.

Showing the sent message until a reflection is received is nice tho.