Protector: Make it difficult to steal images from Web pages

This package can be used to make it more difficult to get images in Web pages.

It provides several protection methods:

- Serve the image with several headers to tell browses to not cache the images
- Avoid hot linking to prevent saving the images when menu mouse button is clicked by the user over the image on the browser, prevent retrieving the with a Web mirroring utility program, display the images typing the URL directly in the browser
- Serve the images with a watermark logo rendered over the image

When an invalid attempt to access the protected images is performed, the class can execute exception actions like redirecting the browser to a given URL or displaying a given alternative image.