V3 for detached headers and key files

[Denis 'GNUtoo' Carikli]

Hi,

Here's the v3 where I fixed the comments.

The additional changes which are not covered by the comments are
mentioned in the individual patches ChangeLogs.

PS: I'm really sorry for the delay. It is due to a combinaison
    of various things (personal issue, urgent things that needed
    to be done, etc).

Denis.