[BusyBox] unarchiving tools reorganised again

[Glenn McGrath]

Ive tested and fixed dpkg-deb and ar and merged in your changes, its 
called unarchive4.diff

So when cpio is working properly i will commit it.

Its best we treat the issue of tar.c and untar.c seperately to the 
unarchive diff, it would be a fairly radical change to the existing 
tar.c and im not sure Erik wants us to mess with tar too much. I was 
thinking maybe the untar.diff could go in a contrib dir ?


Glenn