Image Browser: Create a picture browser

This class is meant to create a complete browser for pictures in the JPEG, GIF and PNG formats.

It features:

- Choosing how many thumbnail pictures are displayed per page
- Thumbnail pictures are created on the fly with a size that is configurable
- Determining which pictures are displayed or not based on their file names
- Showing the current picture number and total count under the picture
- Browsing directories recursively
- Choosing the background color of thumbnail pictures
- You can use your own navigation button or use integrated buttons (there are 4 types of buttons : previous; previous grayed; next ; next grayed)