Fixed Lua error

• Added: Dedicated Admin Pistol weapon model
  
• Added: Slight view punch
  
• Fixed: Getting notification of other player's fire mode change
  
• Fixed: Getting multiple notifications when fire mode changes
  
• Fixed: Prevent NPCs from dropping Admin Weapons and grabbing weaker weapons.

• Removed: Remove Admin Rifle because it didn't prevent NPCs from dropping this weapon and grabbing weaker weapons. There is no need to maintain two identical weapons.

Fixed kill icon sizes

Added Admin Rifle which is based on HL2 AR2.
Since NPCs prefer AR2 than Pistol, I added Admin Rifle hoping that NPCs won't drop their Admin Pistol and grab plain AR2.

• The default secondary fire mode can be set with 'sc_adminpistol_default' ConVar.
  
• 'Armed Grenade Mode' is added.
  
• Now it shows the current secondary fire mode notification.