Fix a bug when receiving a topic change

The number of arguments is not always the same

Possibility to change a channel's topic

Convert received modes into roles and affiliations

Use isupport informations to know the user modes when joining

Also remove the duplicate send_self_join methods, user only send_user_join

Basic isupport support

CHANMODES and PREFIX only

Handle nickname conflicts by sending the correct XMPP error presence

Remove disconnected IrcClients

Keep a "connected" state in the SocketHandler class

Be verbose about the connection status, and some errors

Handle topic changes

Check that channels are joined before acting on objects in it

Shutdown cleanly on SIGINT

Lowercase the chan names in two missing cases

Provide a JID for IRC users, and add a stringprep dependency for this

Enforce a simple limit of 400 bytes for IRC messages body

The limit for the whole message is 512 bytes, we limit the body to 400
(instead of doing a calculation based on the command name and the other
parameters), because it's simple, easy and that’s enough.

fixes #2416

Display all the MODE arguments in the message

Use the logger everywhere

Add a logger class

Fix a parenthesis ambiguity

:3