Adding the comment class
========================

Highlights:
- Adding the ability to add comments to photos, and delete them in admin area

-Files:
- new file:   includes/comments.php
- modified:   includes/database_objects.php
- modified:   includes/functions.php
- modified:   includes/initialize.php
- modified:   includes/photographs.php
- modified:   logs/log.txt
- new file:   public/admin/comments.php
- new file:   public/admin/delete-comment.php
- modified:   public/admin/list-photos.php
- modified:   public/photo.php
- modified:   public/test.php