Lowered NRG regen rate in Player.lua.  Increased default energy cost of Single Shot.
Merge branch 'master' of https://github.com/encephalopathy/wepwep
Adjusted energy costs for Back Shot and Homing Shot. Updated the calculateBulletVelocity() call for Bomb.
Merge branch 'master' of https://github.com/encephalopathy/wepwep