fix #1019

Add support for Unix domain sockets.

This ensures that host:port is used rather than an empty address,
which defaults to 127.0.0.1:3306 (ignoring the host in the config).

This adds a new configuration option, socket-path, instead of using
host.

Revert "Add support for Unix domain sockets"

#1011: recommend allowing webirc from localhost

Add support for Unix domain sockets

make histserv replies come from histserv, not hostserv

fix #1005

fix #858 and #383

fix #1003

upgrade go-ident to fix parsing issue

ratify SETNAME

fix #996

treat channel founder as such even if they don't have +q

Call ApplyUserModeChanges for default user modes.

This ensures that counts like the number of invisible users are updated
correctly.

This affects /TOPIC, /INVITE, and a few others.

As of 3dc5c8de78, the PROXY-before-TLS proxy line
and any proxy information carried in X-Forwarded-For
do not count as the "first line", so an additional
client-supplied PROXY line would have been accepted.

fix #994

fix #952

Hide +i users from WHO * queries.

Construct a hash set of the user's channels and check that rather than
querying channel membership, to reduce the number of locks that need to be
acquired.