Do a natural sorting of items (thanks to Dominic Battre and Martin Pool for the patch!). This means that items like:

 item_10.png
 item_1.png
 item_2.png

are sorted like
 item_1.png
 item_2.png
 item_10.png

TODO: corresponding to Ellen directory items should always be ordered as first items (have to go work now -> weekend task :-))

svn path=/trunk/playground/utils/dolphin/; revision=622241