Arm range fix

Previously, all arm animations were assumed to operate between +-80 degrees, and this was fixed at compile-time in `struct Player::Range`. This change makes arm animations actually depend on the `minLookAngle` and `maxLookAngle` values in the datablock.

Also cleaned up the `updateLookAnimation` function a bit since I was touching it. Basically, `dt` now represents the time delta, as usual.