move signals code to utils/

factor out some shared code

document gamja

rename oragono.io/nope to ergo.chat/nope

Thanks to @cxxboy (#1788)

add # to disfavoredNameCharacters

update logo in /INFO response

Partially fixes #1679, not sure whether to police the relaymsg config or not

(based on 'slant' figlet font with some tweaks)

fix #1530

Warn if the user sent, e.g., /QUOTE /SAMODE instead of /QUOTE SAMODE

add s6 services to distrib

Add support for extended-monitor

fix #1650

RPL_WHOISACTUALLY should display some arbitrarily chosen IP address and
hostname.

* Add email-based password reset

Fixes #734

* rename SETPASS to RESETPASS

* review fixes

* abuse mitigations

* SENDPASS and RESETPASS should both touch the client login throttle
* Produce a logline and a sno on SENDPASS (since it actually sends an email)

* don't re-retrieve the settings value

* add email confirmation for NS SET EMAIL

* smtp: if require-tls is disabled, don't validate server cert

* review fixes

* remove cooldown for NS SET EMAIL

If you accidentally set the wrong address, the cooldown would prevent you
from fixing your mistake. Since we touch the registration throttle anyway,
this shouldn't present more of an abuse concern than registration itself.

remove SCRAM-SHA-256 from advertised SASL mechanisms

Advertising SCRAM-SHA-256 breaks irccloud, which doesn't fall back to PLAIN
if it sees SCRAM advertised but SCRAM then fails (as is the case for any
account password hashed on Ergo 2.7 or lower).

Leave a config option for irctest to enable it in the controller.

upgrade go to 1.17

Add missing argument to ERR_NEEDMOREPARAMS on USER commands.

Refs:

* other instances in the codebase
* https://defs.ircdocs.horse/defs/numerics.html#err-needmoreparams-461
* https://modern.ircdocs.horse/#errneedmoreparams-461

Make kick messages default to the kicker name instead of the kicked

For consistency with RFC2812, Bahamut, Hybrid, Insp, Plexus4, Unreal.
https://datatracker.ietf.org/doc/html/rfc2812#section-3.2.8

At the expense of consistency with chary/solanum, irc2, and ircu2.

Advertise support for multiple KICK targets

This is already implemented, but TARGMAX=KICK:1 says it isn't.

Instead, let's advertise that indefinitely many targets are allowed.
Refs:

* https://defs.ircdocs.horse/defs/isupport.html#targmax
* https://github.com/ircdocs/modern-irc/pull/112

fix handling of +k with an empty key parameter

This should be disallowed; `MODE #keytest +k :` should just be an error.

Add missing channel parameter to ERR_INVALIDMODEPARAM.

bump irctest

Document mute extbans

Fixes #1747.

fix SCRAM not supporting client IDs