Better repodata performance (was: redhat abe)

[mbneto]

Hi,

I think that if we reduce to amount of metadata necessary to transfer
both users and maintainers will benefit.

They will consume less bandwidth and be able to serve more clients and
the users will have faster downloads.

> Oh and once more - who is it gets the benefit from all this work?
> It sounds like it's mostly repo maintainers - not the users.
>