phpAlbum.net 0.4.1-14_fix02

Fixed the bug regarding the screenshots for files reported by Greg(glittle).
Even if there are no screen shots a default "File Download" thumbnail will be displayed. Now you can just place any files in photo directory and they will be visible and downloadable for users.

For updaters:
- The only changed file is main.php, and there is one new file too in res/ directory named file.png.
- No database changes were made so no complications should be awaited :)