Trivial syntax improvements

Throttle all commands sent to IRC servers

fix #3354

Remove an outdated TODO comment

Archive the Mode messages, except if they are received for an unjoined chan

fix #3362

Channels’ disco#info includes the number of participants

fix #3311

Merge branch 'v8'

Do not use (or present to the user) the Address field in fixed mode

fix #3359

Merge branch 'v8'

Handle the NAMES message for an already-joined or non-existing channel

If a user manually does a NAMES query, the result were interpreted as a user
list, which is wrong. And with the special * argument, this would even cause
a crash.

Fix #3357

Improve the forward_server_message to concatenate everything

Pass an IrcClient* to send_muc_leave instead of doing an other search

Allow the execution of multiple commands after the IRC connection

fix #3275

Allow to override the addresses used to connect to an IRC network

fix #3273

Add a <item/> node in the presence of a leaving participant

fix #3339

Remove the virtual channel feature altogether

Merge branch 'patch-1' into 'master'

Change max line length to more conservative constants

See merge request louiz/biboumi!21

Change max line length to more conservative constants

Add support for the "history" node on MUC join

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

fix #3270

Small refactor in on_quit()

Don’t forget to remove the user from the channel, when kicked

fix #3291