Always use lower case filenames when building filenames

Activating this option forces a lowercase conversion on any function that creates a link to a filename. Some examples of when this option would have an affect are: image tags, linking to a file on the system, and linking to a name anchor in another file.

Adopting a lowercase filename convention is a good idea for users who publish to UNIX web servers where filename are case sensitive. This option works well with WS_FTP's option to force lowercase filenames on file upload.