Remove the virtual channel feature altogether

Add support for the "history" node on MUC join

Supports the "seconds", "maxstanzas", "since" and "maxchars" (but only =0)
attributes.

fix #3270

Handle messages 367 and 368 to display the banlist in the MUC

fix #3234

Apply all the clang-tidy modernize-* fixes

Remove two sneaky log_debug

Merge branch 'persistent_chans' into 'master'

Add a Persistent option on channels

Closes #3230

See merge request !6

Add a Persistent option on channels

fix #3230

Pass the shared_ptr by reference, to avoid useless copies

Send a presence error from the room, when receiving command ERR_BADCHANNELKEY

fix #2886

Move all the connect() logic from TCPSocketHandler into a subclass

This way, TCPSocketHandler only deal with the message sending/receiving, not
the connect() or anything else.  This will be used for implementing servers
(because when a client is accepted, we don’t need all the connect() and dns
resolution stuff).

Handle IRC message 341 (invite confirmation)

Forward IRC invites to XMPP

Forward mediated invitations (XMPP to IRC only)

Don’t use ! as the separator for nicknames, use % instead

It’s now easier to use. The distinction between a nick and a channel name is
based on the first character (by default it's '#' and '&'). The user doesn’t
have to worry about which separator to use anymore.

fix #3066

Replace all include guards by #pragma once

It’s $CURRENT_YEAR

Save our own host, as reported by the server

Support multiple nick session, except for IQs

ref #2556

Style fix

Move all constructors at the top of classes

Forward the topic authors, handle the author from 333 messages

fix #2

Support RPL_NOTPIC and 005