Don't treat tags as orphans.

Tags is reachable, searchable and totally accesable. In that sense, they are
quite close to branches. But they can't really be checked out, which is the
difference.

But since they are accessable, keep the commits leading to the tag visible, as
with branches.

Signed-off-by: Max Sikström <msikstrom@op5.com>
Merge branch 'topull'