Modify shock damage in a single manner

- Power gloves cap is now at 1 million watts. Zing
- Shock damage formula is power/rand(4000, 6000) capped to 500, reached
in average at 2.5 million watts. Note to self : Nerf Supermatter Engine
which can still reach 3 million watts
- Sample shock damages : 50000 = 10, 100000 = 20, 500000 = 100. This is
a very simplistic damage calculation but it works