This also deprecates the built-in chat_only configuration option.
If you need this functionality, then load the mod_chat_only plugin (if it is loaded then only operators
are able to search, connect, etc).
Dynamic commands are user commands that can be added dynamically to
the hub by a plugin.
The example plugin (mod_example.c) adds a !example command that when
invoked send a message to the user who invoked it.