Vehicles system 4.3

[Drakath]

This is an update that addresses all known bugs.

Fixed a bug where you would spawn your old vehicle if your old vehicle was spawned before you bought a new vehicle and you did not use the destroy button.
Cursor should no longer disappear if other windows from the vehicles system are active.
Added a confirmation dialog when selling/buying a vehicle.
Players will now be automatically transported to the ground when they are in a helicopter and it is re-spawned or the vehicle's owner leaves the server.
Players will now be able to destroy vehicles that do not have other players inside it.
Improved vehicle locking.
/removecarupgrades now removes vehicle's colors and paintjob.
Many other code improvements and error fixes.