Creates an image control that loads its picture from url; sizes are pixel strings or
fractions of the parent, and a size left out is chosen by the engine.
The name, the URL, the color and the optional size
The image control
Reads the URL an image control loads its picture from.
The image control
The URL
Changes the picture an image control shows by giving it a new URL to load.
The image control and the URL
The same image control
Images shown as GUI controls, loaded from a URL, for logos, icons and pictures beside other controls.