Simplified the prevention of loading the robot_arm package twice.
Added documentation on loading wxLua and on preventing requiring twice.
The robot arm can now move to the right without blocking the rest of the application.
The animation system is now reusable.
The robot arm can now move to the left without blocking the rest of the application.
When the robot arm moves, only the parts of the window that have changes are redrawn.
The robot arm now animates when grabbing a block.
The robot arm moves to the correct height for grabbing the top block on the stack.
The robot arm now animates when dropping a block.
The robot arm cannot be moved to a position that isn't above the assembly line.
When the robot arm tries to grab a block from an empty stack, it animates to one block above of the assembly line.
You can set the speed of the robot arm on a scale of 0 to 1.
Setting the speed to 1 means that the robot arm executes its instruction immediately, without animation.
When grabbing while already holding a block, the robot arm just lowers and raises the block it's holding.
The size of the window depends on the size of the assembly line and maximum height of a stack.
Added a bunch of exercise levels.