LinkRelay: do the same changes as in ProgVal/Limnoria#628 .

## Config chages

Enable colours: most of people want them and they are supported by
all IRC clients used nowadays.

Show hostmask: that is standard behaviour of relaybots which I am seeing.

Punish other relaybots: Does this even need explaining? "Let 2009-11-24 <http://echelog.com/logs/browse/supybot/1259017200> be a lesson to you: turn *on* supybot.plugins.Relay.punishOtherRelayBots."

Don't join on all networks: I think that people mostly want to relay
specific networks, not all of them. This is also a method to evade
limitation of LinkRelay ( ProgVal/Supybot-plugins#11 ).

Use notices with nonprivmsgs: This is also standard behaviour and makes
it easier to see the difference between PRIVMSGs and everything else.

## Other

We are trying to use gender neutral pronouns everywhere else too.