When set to true, the realname and username are extracted (by default) from
the user’s JID

fix #3136

ref #3136

Used in the USER command when connecting to the IRC server, instead of the
first nick.

fix #3028

This let any user choose which ports to use when connecting to the IRC
server. This also lets the user choose whether or not to force TLS usage (by
setting no non-TLS port).

fix #2731

fix #3068

Each IrcClient callback has a max and min size of argument, we call the
callback only if the parsed message has a correct number of arguments,
otherwise it is ignored (with a warning logged).

Some XMPP client ping themselves inside MUCs, to know if they are still in
there, this created a flood of PING message in private.  If the user is
interested in knowing when they receive a ping or version request, they can
still read their XML logs

ref #2472

fix #3041

This way, the users can receive the result of any IRC command (although not
parsed nor formatted in anyway) when biboumi doesn’t support it

fix #2884

Messages received on an IRC server JID are forwarded as raw IRC messages.

fix #2486

Note, in our context, is_connecting() includes the resolving part as well as
the actual connection (if we are using c-ares)

fix #3048

ref #2472

fix #2715

Because we need to wait for the welcome message, when we connect to the
server, before sending the JOIN command, we need to also save the value of
the password to reuse it when we actually send the JOIN command

fix #2882

ref #2757

fix #2576

SocketHandler has been renamed to TCPSocketHandler
SocketHandler is now a simple interface with a few methods, used only by
Poller.

This way we can inherite from the new SocketHandler class, to handle other
types of sockets, and still make them manageable by the poller without any
change in the Poller class.

IRC users and channels are now distinguished by the separator used in the
IID (% or !).

ref #2468

For now, it tries two TLS ports and then connects to the non-tls port.  In
the future we would like the user to be able to configure that.

fix #2435

fix #2452