modifies how far a corpse is from a blob for zombies to occur.

Initially it was bugged to be anywhere in the same area
Then it was only the tile under the blob
Now, thanks to standing corpses and rally spores not always rallying a spore to the exact place you click, it's the same tile or one tile adjacent.
Merge pull request #2954 from Incoming5643/yabbamyicing

Modifies how far a corpse has to be from a blob for zombies to occur.