* Updated utilsController.js: Unlink thumb of type symlink whenever generateThumbs() is called.
* Updated thumbs.js: Add stats (success/error/skipped).
* Patched getFiles() function to regard symbolic link files as nonexistent. By default failing thumbs will create symbolic links to a placeholder image. Previously the script would regard those symbolic links as existing thumbs, thus preventing the script from generating thumbs for those files.
* Added verbose option. Previously the script would print even all files that already had thumbs. Now it would only print files with missing thumbs, and enabling the option would restore the previous behavior.
* Faster upload response. Back-end will no longer wait for album timestamps to be updated before sending out response.
* Added a simple thumbnail generation script at scripts/thumbs.js. You can use this to generate thumbnails for existing files before enabling the option in config.js.
* Various other code improvements.
