Change expansion scoring to stop favoring less exits
Change expansion scoring to stop favoring less exits

* Drop `CITY_WEIGHTS_DEFENSIBILITY` to zero. This was originally set to
two before the wall/rampart program was put together. Since `Quorum`
isn’t actually building exit walls it doesn’t make sense anymore to
take them into account when selecting new rooms.

* Add new `CITY_WEIGHTS_MINERAL_CATALYST` and set it to 3 (two points
from above, and one point taken from CITY_WEIGHTS_MINERAL_MARKET). This
triggers if the room has catalyst. This keeps `Quorum` from ignoring
catalyst on new shards or private servers (where NPC prices tend to
mostly be equal at the start) and helps take into account the rarity of
catalyst.

ScreepsQuorum/screeps-quorum