Using sanctuary, it is possible to teleport into the town even if Tux didn't
ever visit the town before.

Since the chance to get a source book of Sanctuary or a teleporter homing beacon
from the bots is small, using this exploit is unlikely. However, as I
understand, it is possible - especially if Tux does not go immediately into the
town, but kills some more bots beforehand.

Solution:
1. The default teleport destination could be set to CRYONIC LABS until Tux
enters the town for the first time.
2. The North Gate Guard could be forced to rush after Tux at the moment he steps
out of the teleporter room.

I think, solution 1 is preferable within the instory logic. Why should Tux
teleport "home" to a place he never were before?

Maybe we should not have either drop from bots?

item_archetyles.dat:
"Source Book of Sanctuary" has a chance to drop for level 2-9 bots
"Teleporter homing beacon" does not drop

Neither are on the map, except for level 24 (testing level).

A simple way to address this would be to prohibit the "Source Book of Sanctuary"
from dropping from bots.

Fixed in r5097 .