auto: should use the minimum subset of versions for a repo

[XaF]

Right now, using 1.22 in a directory and 1.22.1 in another would lead to two versions installed if the latest 1.22 is not 1.22.1. We should make sure this does not happen as 1.22.1 does fit the 1.22 requirement, and we should thus try and use the minimum number of versions possible.