Hints for improvement
1. Great program. It works fine.
2. The name conditions for directories (data, cache and photos) aren't quite clear. On one hand two of them should be random, but in documentation and web-installer (works fine) they all have the same structure (function_random). Is this necessary? Why should I change the cache-directory in main-setup?
To my opinion the cache-directory could be defined one time in config.php too.
3. When I use a directory with subdirs and only the subdirs contain pictures and I use thumbnails for dir-symbols, there will be the information "No Files found" - even if there are 3000 pictures in subdirs. Its correct, but it could irritate visitors.
Is there any possiblity to use thumbnails as default and only empty directory are presented by dir-symbol?
Sorry for my English.