Two more drugs

Adds:
- Jenkem
- Cat Drugs

Jenkem makes the user touch fuzzy and get dizzy. Also has 50% chance of dealing small tox damage.

Cat drugs work like hyperzine except they make the user meow and hiss. Novelty more then anything.

Assuming you meant 1-4 and not all ```cat1.ogg```, this might be nicer:
```dm
    playsound(get_turf(src),pick(
        pick(
            'sound/effects/cat1.ogg',
            'sound/effects/cat2.ogg',
            'sound/effects/cat3.ogg',
            'sound/effects/cat4.ogg',
            ),
        50,1)
```