[physfs] r503: uninstall progress running backwards

[Ryan C. Gordon]

(moved over from physfs mailing list.)

> uninstall progress meter was running backwards (delete_files() starts at the
>  end and works to the start). Fixed to run forwards.
> ------
> 
> I thought this was a feature? (Honestly)
> Install goes into the system (to the right), uninstall goes from the system 
> (to the left)...

My thought was that progress bars should always increment (the delete 
operation is 75% complete", not "you have 25% of your files left"). I'm 
not sure they should run backwards, for consistency.

--ryan.