Add examples
new file:   ch26/item08/Blur.java
new file:   ch26/item08/Contrast.java
new file:   ch26/item08/Convolver.java
new file:   ch26/item08/Grayscale.java
new file:   ch26/item08/ImageFilterDemo.java
new file:   ch26/item08/Invert.java
new file:   ch26/item08/LoadedImage.java
new file:   ch26/item08/PlugInFilter.java
new file:   ch26/item08/Sharpen.java
new file:   ch26/item08/TileImage.java
new file:   ch26/item08/picasso.jpg
new file:   ch26/item08/vincent.jpg
new file:   ch26/item09/Animation.java
new file:   ch26/item09/earth.gif
new file:   ch26/item09/earth.htm
new file:   ch26/item09/horse.gif
new file:   ch26/item09/horse.htm