[AD] Forced absolute grabber/dat object origin paths

["Hajie" <hajie@xxxxxxxxxx>]

-- 
In allegro 4.0.3, it seems relative paths (eg "../blah.bmp") are not 
understood by dat or grabber for paths at which to grab data.  Version 
3.12 (DOS only) seems to support this and I was wondering if support 
could be added again for it?  Also, is there a way for paths to be 
platform-independent?  Ie, for front-slashes to be understood by unix 
and non-unix platforms so that I can use makefiles to grab my data with 
dat.

Thanks.
-Hajie