add a zombification chem to the traitor poison bottle pool

[aft2001]

I'd like this a lot, and would be even more interesting if it zombified people over a short amount of time and not immediately, so more chances to spread it before being a horrible zombie!

Also maybe as an expensive MedSci traitor vial that has that symptom for Pathology, but that symptom can't be found anywhere without it (well, maybe deep in space) BUT it requires you to splice the gene into a disease you built and engineered.