Oops, little mistake in the spawner gave an error, fixed.

- more performance updates and tweaks
- lesson spots no longer reserve the same spot in parts rack leading to engines on the floor
- car parts rack is now optional if you decide to make a garage with only paint spots
- more detailed tooltip on the gantry crane booth, showing what's going on in the garage
- several minor bugfixes

- car hoods no longer exist as separate objects as mentioned below.
- gantry crane now continues doing its job and resets some more values if it was busy grabbing a car or an engine while the object was sold by the player.

- vehicles use a new way to find each other while using less cpu cycles to do so
- vehicles are now aware of the position of their head/tail lights and of the lights of other vehicles to be able to better calculate distances between other vehicles and road gates
- gantry crane can now do tasks in a batch, instead of having to park between jobs
- the Delete Garage button on the booth should now get rid of all items (it was missing a few)
- added missing sprite for the small road pole in the garage
- and probably some more things which I forgot to mention...

- Trucks can now leave as soon as their cargo has been unloaded, no need to wait for the crane to park first.
- Objects are now only searched for when needed, instead of loading everything at start. This should improve map loading a little bit.
- Some small bug fixes in lesson car and limo on floor.

- optimized truck script, it should be using less cpu cycles than before.
- trucks will now blink the direction light when arriving at their garage or when they are ready to leave their garage. A truck may not leave his parking lane immediately, because it has to wait for repaired limos first.
- in tall garages, the truck will now keep driving until the end of the parking lane before returning to the main road.
-truck driver no longer operates the crane, only the crane operator will do this.
- truck driver now hangs out in the limo waiting room instead of the garage.

- added military drivers and lesson cars
- tweaked some tooltips and the way how a repaired limo finds its driver

- a repaired limo on the floor will spawn a limo when the driver got in and it then deletes itself.... But the spawned limo would somehow be able to find his deleted predecessor and think that this is his vehicle in front of him. Resulting in a limo driving around with an unknown vehicle in front, and a vehicle in front not being aware of the limo behind. Nailed you damn bug!

workaround for JobComplete() being executed before Update() when loading the map.

- Added a third gate in the garage, so vehicles will wait when a repaired limo is put on the road.
- various little bugfixes/improvements...