Clean HTML Site Paths

This modules uses the drupal_alter to provide CDN like rewriting of site image paths. This allows a site owner to remove the /sites/default/files path and replace it with a defined Apache/Nginx alias. This is a common requirement for multi site setups. The hook_file_url_alter() appears to be documented in d7, but not in d6. This uses core hooks to alter the paths before output. Some of the features were adapted from the CDN path rewrites that allows sites to utilize content distribution networks and their URL logic.