#416 Add messageboard graphics and arch and use them

[Saiapatsu]

The patch for /arch/ will add archs, images and faces for messageboard, messageboard_red and messageboard_say_event.
The patch for /maps/ will replace all talking signs with messageboard or messageboard_red archs with appropriate names for them and their events.

Most of the work was done using this regex replacement (global; dot does not match newline):

arch sign
name (.+)
msg((?!endmsg)[\s\S])+endmsg
x (\d+)
y (\d+)
arch event_say
name (.+)
title Python
slaying /python/IPO/board.py
end
end

---

arch messageboard
name \1
x \3
y \4
arch messageboard_say_event
name \5
end
end

msg((?!endmsg)[\s\S])+endmsg matches msg, then anything but endmsg, then endmsg.
[\s\S] matches anything (unlike .)

Maps with DM message boards:

HallOfDMs
navar_city/misc/highcourt
santo_dominion/city_hall
scorn/misc/cityhall (also moves the board and its buddy one tile northward to be less crowded with the statues)

Some potential snags:
The patch doesn't update the Modified: field of most affected maps.
The board archs have the same subtype as the sign, which might cause trouble in the future, when readable background images are added.
The board event pollutes the readables arch list. It's not really a sign, but it appears alongside them. Or maybe these lists aren't meant to look nice like pickmaps.

[Saiapatsu]

And a choice for a DM board that's colored a more saturated red:

[Nicolas Weeger]

Committed as 15a0fcb70bc1180247d29fc617804f9fc1408372 (arch) and fbf5fbb902b29d4fd2357e4101d4d73a62e05881 (maps), thanks!