Removed some doors
Added chat prefixes option for IRC chat

A prefix can be set via settings.json which, if set, will only
send/receive IRC chat if the message starts with that character. The
setting is specified with an ASCII integer (not string, though that may
work).
Adjusted death code slightly

Should result in more descriptive death reasons again.

Taken into account bleedouts now, the took-damage tick isn't checked,
only the last hit-by ID/weapon.