screenShotRGB: Make a Screenshot using Robot Java Class

Creates an RGB color image with 'uint8' class elements read from the screen. You can define a rectangle to make the capture.
The function uses the Java class 'Robot' to do the screenshot.
For example, make a screenshot of the entire screen, plot and save it to a
file:
im = screenShotRGB; % make the screenshot
imwrite(im,'screenShot.png');
figure
image(im);
axis equal, axis tight
axis off

For more information about the Robot Java class see:
http://download.oracle.com/javase/1.4.2/docs/api/java/awt/Robot.html#createScreenCapture%28java.awt.Rectangle%29