some small fixes/enhancements

RELAYMSG should respect mutes

Improve error message for CS TRANSFER

PerstentStatusMandatory should display as "enabled", not "mandatory",
in the context where it refers to a user-chosen setting.

Allow chanops to delete channel messages from history

Handle panics in rehash, even if it was triggered by SIGHUP

bump irc-go again

Fix link to productionizing guide.

bump irctest

deprecate message truncation

Implements #1577, but the issue should remain open until we clean up
the debugging loglines.

fix #1584

See #1584

Send 477 ERR_NEEDREGGEDNICK when an unregistered user messages a +R user.

Minor documentation updates.

docs/MANUAL.md: add recommendation for proxy timeout

The +M channel mode is documented twice. Merge the two sections.
Clarify that +R restricts both joining and speaking, but does not kick existing unregistered users.

Fixes #1064.

Resolves: #1578

implement candidate compromise proposal for websockets

update the FAQ to cover some controversial issues

fix #1547

make PASSWORD an alias for PASSWD in nickserv

bump irc-go to fix buffering issue

fix #1559

validate that passphrases are valid as non-final IRC parameters

New Crowdin updates

bump irctest to latest upstream master

improve compatibility with published register spec

1. Send COMPLETE_CONNECTION_REQUIRED instead of DISALLOWED
2. Include the account name in all FAIL messages

fix #1563

ERR_INVALIDMODEPARAM should take both the mode and the invalid parameter
as arguments.

As of #1483, websockets entail enforce-utf8, so there's no need
to check globalUTF8EnforcementSetting when handling websockets.

Improve debuggability of some config deserialization errors

1. Text and binary frames are accepted
2. Text frames are sent by default
3. Binary frames are sent to clients who negotiate `binary.ircv3.net`
4. Non-UTF8 data is not accepted (enabling websockets still enables UTFONLY)

bump irc-go to latest