Also:
- Add get_conversation_messages() to PluginAPI
- Make plugins_autoload colon-separated instead of space-separated
(for consistency)
- Replace a JID() with a safeJID() in the uptime plugin
- add methods related to timed events to the PluginAPI
- remove parse_command_args_to_alias because str.format does that, and
better
→ update the alias plugin