Update 2018-06-26: Mouse options and pen mechanic updates

• Added mouse options: sensitivity and Y-invert
• Added normalization mechanic to kinetic penetrators
• Added ricochet mechanic for all ammo types, with varying angle tolerances
• Improved spall spray patterns
• Changed spall fragment sizes to better reflect reality
• Changed ERA detonation behavior - now disappears on impact
• Improved armor model of T-90 (still WIP)
• Buffed T-90 turret cheeks
• Nerfed M829A3
• Reduced height of turret throws