:rtype:list of (string, string) tuples containing the nickname followed by their public key
Commands
========
..function:: execute(command, class)
Execute the given command, where a class of 0 indicates a global command, 1 indicates a chat command, and 2 indicates a groupchat command.
:param command:The command to execute.
:type command:string
:param class:The class of the command.
:type class:int
:rtype:none
..function:: register(command, help, callback)
Register a callback to be executed whenever command is run. The callback function will be called with one argument, a list of arguments from when the user calls the command.
:param command:The command to listen for.
:type command:string
:param help:A description of the command to be shown in the help menu.