Ideas used:
* Directory structure should match that of the data dir
* The unsorted directory contains files that don't have a defined place to go
 (or you just don't want to sort)
* Data files should have their source files in the mirrored media dir, as well as similar
 or alternate versions
* Things that look (don't actually have to be) like screenshots or annotated screenshots
 go in images/screenshots
* New badguys or object things go into their images/objects or images/creatures dir
* Images not covered by any of the above go into images/sketches
* If an image almost fits, but isn't exactly, assume it is anyway.

SVN-Revision: 5731