Thumbnail standard

[Sean 'Shaleh' Perry]

>
> We do not current rely on the mtime of the thumbnail. In addition, unix
> already keeps track of the latest access to a file. Its called "atime"
> (stored in st_atime in struct stat). Check your thumbnail directory out
> with the "stat" command. Or try e.g. "ls -ltu ~/.thumbnails/normal/" to
> see which thumbnails you used most recently.

do not count on atime for any file.  NFS does not always keep it up to date 
and many laptop users disable atime writing to prevent their disks from 
spinning.