Fix pulse lmg fire rate

Nerf fire speed of Sniper（0.66~0.975）
Nerf Heavy Shotgun Damage (125~50, 100~50, But still have 10%~20% to kill player in one shoot)
Nerf Automatic Shotgun Damage（45~36,255 RPM~198 RPM）
Fix AR2 Sound issue

Important Update:
Add New Enemy: Spike Wall from Patient Zero with Super Heavy Armor and Dangerous Super Heavy Shotgun
Blind Grenade comes back from old Combine Units +PLUS+, it is equipped with Elite Commando and Spike Wall
Buff Elite Snipers' fire rate, add new skill that Sniper can set Combine Mine（Thanks for WaWa574）
Nerf Heavy Operator, you can deal minor damage to it when shooting its body
Combine Commander can heal his teammate and other combine soldiers
Combine Medic can deploy Heal Bomb as usual
Combine Commando's Shotgun switch to normal shotgun because Heavy Shotgun has bug when change weapons
Combine Gas Team's pulse pistol change into shotgun
Elite Sniper has new camo model from Military Combine
Nerf Suppressors' and Heavy Operators' Shotgun because they are too overpowered to player（although they are still deadly)

Fix Auto Shotgun's texture

Add new anim to Heavy Operator
Enhance Heavy Operator's weapon, they have high fire rate APF Weapon and new automatic shotgun to make them more deadly and suppress enemies more effectively
Nerf Elite Medic heal themselves
Overseer have more bullet proof and stay with their team

Update:
Nerf Heavy Operator Health(100~50)
Buff Supporter's fire rate and Grenadier's damage(40~50)
Nerf Grendier's effect because original effect is too overpowered
Add damage protection to Overseer, Support and Grenadier
Fix NPC replacer weapons that replaced npc will use original and weak weapons like smg1 and ar2 instead of their new unique weapons

重要更新：毒气弹从老版本的CMB U+中归来，并且添加了新的精英变种和新的黑色毒气弹
略微提高了重武器手的伤害
更换了反坦克步兵的模型
新增霰弹手枪，为毒气弹步兵使用

Improve Heavy Shotgun spread to make it deadier
Change grnadier model
Buff Combine Heavy Operator