Item Update

Update Notes:

Items:

• Added items
• Disk items launches a high velocity disk in the same direction of the car
• Grenade item after 4 seconds it explodes, sending cars into the air
• Blue Rocket homing rocket targeting the place in front of you
• Purple Rocket homing rocket targeting First place

Lighting:

• Removed baked lighting

Races : 

• Fixed checkpoint system to work with items