[AD] Relative filenames in dat/grabber utilities

[Eric Botcazou <ebotcazou@xxxxxxxxxx>]

I just checked in on mainline what I hope is the final patch needed in order 
to enable full support of relative filenames in the dat/grabber utilities. 

It required more work than initially envisioned because you need to make sure 
that absolute filenames are kept as long as possible because you need two 
absolute filenames to calculate a relative filename independently of the 
working directory. I also cleaned up the internal interface for the datedit 
code.

Moderately tested on Windows and Linux and applied.

-- 
Eric Botcazou

Attachment: dat_relative.zip
Description: Zip archive