Walkabout: Enable scripting for all doors

[culacant]

All door scripts should be turned on when loading a world.
We can easily enable all scripts everywhere, but since we still have lots of function calls stubbed, this would spam errors all over.
To prevent this, make a list of door object ID's per world, when we load a world enable scripting on these.

Implementation in WorldLoader:

• when a new world is loaded, loop through the list of script-enabled objects and enable scripting