GitLab

add optional muc_list to configuration of simple_notify, as a whitelist of MUCs you want to be notified from.

(use automodule directive & docstrings)

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

Plugins do not need to escape the command arguments or remove the line
breaks and care about how the will get parsed anymore, they just need to
pass a list of args.

Do not spawn an additional shell, for more clarity, simplicity and possibly
security.

Improve the simple_notify plugin and the daemon to execute a command to clean the notification and to execute the remote commands through sh -c, letting us use pipes and redirections. Also adds the highlight event for plugin, and make the simple_notify plugin use it as well.