* Makefile: Add dependencies between targets

* Implement draft/message-redaction for channels

Permission to use REDACT mirrors permission for 'HistServ DELETE'

* Error when the given targetmsg does not exist

* gofmt

* Add CanDelete enum type

* gofmt

* Add support for PMs

* Fix documentation of allow-individual-delete.

* Remove 'TODO: add configurable fallback'

slingamn says it's probably not desirable, and I'm on the fence.
Out of laziness, let's omit it for now, as it's not a regression
compared to '/msg HistServ DELETE'.

* Revert "Makefile: Add dependencies between targets"

This reverts commit 2182b1da69.

---------

Co-authored-by: Val Lorentz <progval+git+ergo@progval.net>

* Add ACCEPT-tracking functionality (authorizing users to send DMs
  despite +R or other applicable restrictions)
* Sending a DM automatically accepts the recipient
* Add explicit ACCEPT command

Co-authored-by: Mikaela Suomalainen <mikaela@mikaela.info>

fix help for +f mode

HELP responses weren't taking the client nickname as a parameter,
as is standard.

Add chanmode preventing speech to error message.

Fixes #1182.

1. DRY "banner" descriptions of each services
2. `/HELP NICKSERV` now refers the user to `/NICKSERV HELP`, etc.
3. Fix double translation of `textGenerator` output

reported by bogdomania

1. Handle PROXY lines with IPv6 addresses starting with ::
(similar to WEBIRC in issue #211)

2. Strip v6 mapping from v4 addresses when handling proxied IPs.