Building 4.x releases on 5.x and 6.x

[Maxim Sobolev]

Does anybody knows if subject is possible? I guess that it is not due to 
usage of vn(4) in the release building process, has anybody any insights 
about actual state of things and/or another potential problems in mind. 
If the only problem is vn(4) vs. md(4), I think it can be solved quite 
easily, while providing a good way to avoid having separate test 
machines for oldest branches.

-Maxim