User allowed to initialize robot positions outside arena

[jtebert]

There is no check whether the coordinates specified by robot_init(x, y, theta) is valid (i.e., within the arena dimensions).

Fix: The code should provide a warning or exit if a position is outside the arena bounds.

This might be easier said than done because when calling robot_init, the Robot does not have access to the World in which it exists.

[r-barnes]

Maybe do a check in world.add_robot() and throw an exception if it fails?

[jtebert]

world.add_robot() is called before robot_init() (because robot_init() calls the Robot's setup() function, which can do things dependent on the world, such as light detection). So there's a bit of a circularity issue here.

[r-barnes]

I see - sorry I missed that the first time.