Movement speed

Changes how hyperzine/nuka cola behaves:

-Hyperzine metabolism lowered from 0.4 to 0.2
-Hyperzine/nuka cola increases your movement speed by one level.
-Hyperzine/nuka cola no longer prevent you from being encumbered

Essentially it's a speed boost chem now, but if you've taken damage you're still going to be slowed. That is to say, it's far far more effective and useful if you're not slowed by anything and are at full health, but if you're wearing a whole bunch of gear/heavily damaged, it's not going to be nearly as effective as it was before.