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

Fix a missing include for strlen

Properly calculate the maximum size of each message line, before cutting

fix #3067

Save our own host, as reported by the server

cut messages at 512 bytes, taking into account the UTF-8 codepoints

ref #3067

Refactor, test and improve the way we cut too-long messages for IRC

Show off, with some variadic templates, for the logger module

Support multiple nick session, except for IQs

ref #2556

Forward everything to all concerned XMPP resources

Use “using” instead of typedef

Forward the topic authors, handle the author from 333 messages

fix #2

Support RPL_NOTPIC and 005

Move the irc callbacks into the cpp file

Support a trusted SHA1 fingerprint to be configured for each IRC server

Support multi-prefix

See http://ircv3.net/specs/extensions/multi-prefix-3.1.html
ref #3103

Use references instead of raw pointer, to store the “parent” object

In Bridge and IrcClient

Add the outgoing_bind option

Lets the admin choose a local address to bind each outgoing (IRC) socket.

Provide an adhoc option to let user pass the cert verif for some IRC servers

Fix the initial IRC nickname (was using realname, by mistake)

Implement a basic webirc support

See https://kiwiirc.com/docs/webirc

fix #3135