Adds ghost writing, config options, redid blood paths/xenoblood.

- Numerous fixes from master.
- Server config options for ghost writing have been added.
- Ghosts on cult rounds can write in blood if admin have toggled it and a certain number of cultists are active.
- Xeno blood code is now descended from human blood code. Icons have been cleaned up accordingly.
- Robots now use blood/gibs paths in preparation for later modifications.
- Robot gibs render correctly.