tests/test-addremove.out

Fix up parent display in logging

For changesets with a first parent nullid, but not rev 0, we ought to
display a null parent.

adding dir/bar
adding foo
dir/bar
foo
adding dir/bar_2
adding foo_2
dir/bar_2
foo_2
adding a
adding c
adding b
adding d
removing a
removing c
recording removal of a as rename to b (100% similar)