Address possible confusion about getBounds() in djutils-draw

[averbraeck]

It is not clear whether the getBounds() methods of drawable objects return absolute coordinates, or relative coordinates respective so some point (e.g., the centroid). The latter is used by dsol; the former is what you would intuitively expect. The comments state: "Retrieve the bounding rectangle of the object", which does not make it any more clear.

Research different options:

• split getBounds() into getRelativeBounds() and getAbsoluteBounds()
• just improve documentation
• see what to do when an object is translated or rotated on the screen -- what are its bounds?

No matter what we choose, the method's javadoc HAS to be made more clear.