Improve contextualized commands (between different tabs)
Having distinct commands between the different tabs (MucTab, InfoTab, ConversationTab, etc.) is often source of confusion, and is quite annoying. Commands being slightly different from one tab to another, commands for InfoTab not being accessible from a MucTab (even though there's no such command in MucTab), etc.
Individual commands can be improved to include more or less context depending on the Tab, and error messages can also be improved to tell the user why a command is not available (and where/how it can be used).
To help progress with this, individual commands should have their own issues.