Add a Git .mailmap

...to make `git shortlog -es` look nicer.
Skip cidr checking for bans with negative or too large cidrlen.

Upto some length, such bans could match the exact IP address.

Obtained from: ircd-ratbox (androsyn)
Also restrict cidrlen for testmask/masktrace (match_ips()).
Skip cidr checking for hostmask.c entries with negative cidrlen.

They will be treated as hostmasks only. In the case of dlines they will
be rejected as invalid.

hostmask.c entries such as dlines, klines and auth blocks can only be
added by opers or via ircd.conf.
whowas: Abort listing if 90% of sendq is in use.
Cope with rb_crypt() returning NULL.
Merge branch 'mailmap' of github.com:grawity/forks.charybdis
stats l: Don't care about away status.
UID/EUID: Check that the UID starts with the server's SID.

If not, the local link that sent the command is broken, as with
syntactically invalid UIDs.
UID/EUID: Add server's SID to invalid UID error message.
Atheme is not responsible for the mental health changes of IRC operators using charybdis.
whois: Fix UID leak.

The second parameter of WHOIS is always a nick.
Mostly enable support for checking format strings with -Wformat.

Basically derived from Ratbox 3.1.
Don't send ERR_NICKCOLLISION to a user that will not be killed.
Update .depend files.