Download count carries over even when changing file

Issue Summary

I keep disknodes for file downloads, these are updated on a regular basis with new versions and thus new filenames. However changing the file will change the download count as download count is associated with FID and not NID. This makes sense as a disknode can have several files associated with it, still it would help me tremendously if one could somehow carry over the download count or set the base download count when specifying the files for a disknode, say a format like this:
//folder/filename.zip [123] where 123 denotes 123 downloads.

You can view my download page here:
http://www.jakob-persson.com/downloads