You can perhaps get some info on features history by reading the "CHANGES" and "Changelog" files on the download page, or browse the CVS tree (click on the version number, not the filename, to read the file).
I don't think there's any "complete history" written up anywhere. I could perhaps do a partial job, but I'm not in the mood right now. Sorry.
Something in particular you need to know?
Best,
Frank
