A small but usefull spam/flood form submit protection. This class can produce a image with a random string and a form input. When the form is submitted, the string from the form input can be matched against generated string in the image. When they match, the submition can proceed. The random generated image string will be matched against a session var or against a file on the server disk, depanding on the backend you've choosed. Default backend is the session backend. Some of the features: * One or more random colors. * One or more random TTF fonts. * Random rotation. * Custom background color or image. * Transparent background with anti-alias of string. * Hardcoded or variable (liquid) dimentions of the image. * Colors can be filled as HEX or as RGB values. * String/code type can be only numbers, only letters or both. * Backend by session or server disk space.