Disease/effects standardization 1

As per #8230. I'll be doing this in small chunks and PRing them separately. Eventually I'd like to move every disease into effects.

This one in particular contains:
* removes some unused disease enums (the old martial arts buffs,the deaf status condition).
* DI_CONTACTS is now an effect.
* DI_BOOMERED is now an effect, `will_vomit()` is currently duplicated in two places.