Sets the position of this Game Object to be a random position within the confines of the given area.
If no area is specified a random position between 0 x 0 and the game width x height is used instead.
The position does not factor in the size of this Game Object, meaning that only the origin is guaranteed to be within the area.
The x position of the top-left of the random area.
The y position of the top-left of the random area.
The width of the random area.
The height of the random area.
This Game Object instance.