Extras repo cleanup

[seth vidal]

> I'm wondering that core/devel and core/fc4 is clean - no old pkgs (where 
> it would be needed much more than in extras); But in extras/devel and 
> extras/fc4 we keep older pkgs.
> 
> However, I would suggest
> 
> fedora/extras/4
> fedora/extras/4_old
> fedora/extras/development
> fedora/extras/development_old
> 

1. it would mean touching packages already in the tree on EVERY update
push
2. it would mean A LOT more traffic for the mirrors b/c rsync doesn't
know about 'move this file to this subdir'

-sv