Ocamlbuild: make log printing code tail-recursive

Patch by Frédéric Bour

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14716 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
[minor] auto-generate a .gitignore using `git svn show-ignore`

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14717 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02