.depends file was generated by an ugly rule that executed the ocamldep
command instead of returning it for later execution. Moreover this execution
was in order to read the output and store as a side effect. By doing this it
was more complicated to work with this command. Now the rule just returns the
command to execute as for other rules. And that's clients that wants
dependencies of a file that trigger the reading of this file.
git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@8566 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02