Add "conflicts:" where needed.
Merge remote-tracking branch 'origin/master'
Update milter 1.0.0 using oasis2opam.

The maintainer's email was changed by hand because no email is present
in the _oasis file.
Remove the conflict spf ↔ milter (milter fixed).
Update utop and remove conflict with optcomp.
Merge pull request #618 from Chris00/master

 Add "conflicts:" where needed.